SPB

4. In the given figure, AOB is a diameter of the circle with centre O and AC is a tangent to the circle at A. If ∠BOC = 130°, the find ∠ACO. 5. PA and PB are tangents from point P to the circle with centre O as shown in figure. At point M, a tangent is drawn cutting PA at K and PB at N . Prove that KN = AK +BN 6. In the given figure, PQ and PR are tangents to the circle with centre O such that ∠QPR = 50°, find ∠OQR. 7. In the given figure, AOB is a diameter of the circle with centre O and AC is a tangent to the circle at A. If ∠BOC = 130°, the find ∠ACO. SHORT ANSWER TYPE(II) QUESTIONS (3 MARKS) 8. In the given figure, if AB = AC, prove that BE = CE. 9. Prove that the tangents drawn at the end points of a chord of a circle make equal angles with the chord. 10. In Figure a q u a d r i l a t e r a l ABCD is drawn to circumscribe a circle, with centre O, in such a way that the sides AB, BC, CD, and DA touch the circle at the points P, Q, R and S respectively. Prove that AB+CD = BC + DA [51]

11. Prove that the tangents drawn at the ends of a diameter of a circle are parallel. 12. In ∆ABC, AB = AC. If the interior circle of ∆ ABC touches the sides AB,BC and CA at D, E and F respectively. Prove that E bisects BC. 13. From an external point P, tangents PA and PB are drawn to a circle with centre O. If ∠PAB = 50º, then find ∠AOB LONG ANSWER TYPE QUESTIONS (5 MARKS) 14. A circle is inscribed in a ∆ABC, with sides AC,AB and BC as 8 cm, 10 cm and 12 cm respectively. Find the length of AD,BE and CF. 15. Two tangents TP and TQ are drawn to a circle with centre O from an external point T . Prove that ∠PTQ = 2∠OPQ 16. Prove that opposite sides of a quadrilateral circumscribing a circle subtend supplementary angles at the centre of the circle. 17. Two tangents PA and PB are drawn from an external point P to a circle with centre O, such that ∠APB = x and ∠AOB = y. Prove than opposite angles are supplementary. 18. In figure, PQ is a chord of a circle O and PT is a tangent. If ∠QPT = 60°, find ∠PRQ. 19. Prove that the intercept of a tangent between a pair of parallel tangents to a circle subtend a right angle at the centre of the circle. 20. A triangle ABC is drawn to circumscribe a circle. If AB = 13 cm, BC = 14 cm and AE = 7 cm, then find AC. [52]

AREAS RELATED TO CIRCLES VERY SHORT ANSWER TYPE QUESTIONS (1 MARK) Choose the correct option: 1. The area of a circular ring formed by two concentric circles whose radii are 5.7 cm and 4.3 cm respectively is (Take p = 3.1416) (a) 43.98 sq. cm. (b) 53.67 sq. cm. (c) 47.24 sq. cm. (d) 38.54 sq. cm. 2. In the adjoining figure, OABC is a square of side 7 cm. OAC is a quadrant of a circle with O as centre. The area of the shaded region is (a) 105 cm2 (b) 385 cm2 (c) 49 cm2 (d) 115 cm2 3. A sector is cut from a circular sheet of radius 100 cm, the angle of the sector being 240°. If another circle of the area same as the sector is formed, then radius of the new circle is (a) 79.5 cm (b) 81.5 cm (c) 83.4 cm (d) 88.5 cm 4. If the sector of a circle of diameter 10 cm subtends an angle of 144° at the centre, then the length of the arc of the sector is (a) 2 πcm (b) 4 πcm (c) 5 πcm (d) 6 πcm 5. If the radius of a circle is diminished by 10%, then its area is diminished by (a) 10% (b) 19% (c) 36% (d) 20% 6. If the perimeter of a semi-circular protractor is 36 cm, then its diameter is (a) 10 cm (b) 14 cm (c) 12 cm (d) 16 cm 7. The sum of the areas of two circle, which touch each other externally, is 153π. If the sum of their radii is 15, then the ratio of the larger to the smaller radius is (a) 4 : 1 (b) 2 : 1 (c) 3 : 1 (d) None of these 8. If the area of a semi-circular field is 15400 sq m, then perimeter of the field is: (a)160 √2 m (b) 260 √2 m [53]

(c) 360√2 m (d) 460 √2 m 9. In a circle of radius 14 cm, an arc subtends an angle of 45° at the centre, then the area of the sector is: (a) 71 cm2 (b) 76 cm2 (c) 77 cm2 (d) 154 cm2 10. A race track is in the form of a ring whose inner and outer circumference are 437 m and 503 m respectively. The area of the track is (a) 66 sq. cm. (b) 4935 sq. cm. (c) 9870 sq. cm (d) None of these SHORT ANSWER TYPE(I) QUESTIONS (2 MARKS) 11. In the given figure, two concentric circles with centre O have radii 21 cm and 42 cm. If ∠AOB = 60°, find the area of the shaded region. (Use π = 22/7) 12. A chord of a circle of radius 10 cm subtends a right angle at the centre. Find area of minor segment. (Use π = 3.14) SHORT ANSWER TYPE(II) QUESTIONS (3 MARKS) 13. In given fig., O is the centre of a circle. If the area of the sector OAPB is 5 times the area of the circle, find the 36 value of x. 14. In the given figure, AB is the diameter where AP = 12 cm and PB = 16 cm. Taking the value of π = 3, find the perimeter of the shaded region. [54]

15. A round thali has 2 inbuilt triangular katoris for serving vegetables and a separate semi-circular area for keeping rice or chapati. If radius of thali is 21 cm, find the area of the thali that is shaded in the figure. 16. In the figure, O is the centre of circle such that diameter AB = 13 cm and AC = 12cm. BC is joined. Find the area of the shaded region. (Use π = 3.14) LONG ANSWER TYPE QUESTIONS (5 MARKS) 17. In the given figure, TPQR is an equilateral triangle of side 8 cm and D, E, F are centres of circular arcs, each of radius 4 cm. Find the area of shaded region. (Use π = 3.14 and √3 = 1 · 732) 18. In fig., ABCDEF is any regular hexagon with different vertices A, B, C, D, E, and F as the centres of circle with same radius 'r' are drawn. Find the area of the shaded portion. 19. Four equal circles are described at the four corners of a square so that each touch two of the others. The shaded area enclosed between the circle is 24 cm2. Find the radius of 7 each circle. 20. In the fig. AC=BD=7cm and AB=CD=1.75cm. Semi-circles are drawn as shown in the figure. Find the area of the shaded region. (Use π = 22/7) [55]

VERY SHORT ANSWER TYPE QUESTIONS (1 MARK) Q.1 Write the HCF of the smallest composite number and the smallest prime number. Q.2 Check whether the rational number 1, has terminating recurring or 13 non-terminating recurring decimal expansion. Q.3 If the HCF of 35 and 45 is 5, LCM of 35 and 45 is 63 x ������, then find the value of ������. Q.4 Express 1001 as a product of its prime factors. Q.5 If HCF of two numbers is 2 and their product is 120, find their LCM. SHORT ANSWER TYPE(I) QUESTIONS (2 MARKS) Q.6 If 13 is a rational number, find the decimal expansion of it, which terminates. Q.7 125 Q.8 Q.9 Check whether 4������, where ������ is a natural number, can end with the digit 0 for any natural Q.10 number ������. Find the HCF and LCM of 6, 72 and 120 using the prime factorisation method. If 241 = 241 , then find the values of ������ and ������. 4000 2������5������ where ������ and ������ are non-negative integers. Hence, write its decimal expansion without actual division. What is the condition for the decimal expansion of a rational number to terminate? Explain with the help of an example. SHORT ANSWER TYPE(II) QUESTIONS (3 MARKS) Q.11 Show that 3√2 is an irrational number. Q.12 The length, breadth and height of a room are 8 ������ 25 ������������, 6 ������ 75 ������������ ������������������ 4 ������ 50 ������������ respectively. Find the length of the longest rod that can measure the three dimensions of the room exactly. Q.13 Find the HCF of 180, 252 and 324 by using Euclid's division lemma. Q.14 Two tankers contain 850 L and 680 L of petrol, respectively. Find the maximum capacity of a container which can measure the petrol of either tanker, in exact number of times. Q.15 Show that the square of any positive odd integer, is of the form 4 ������ + 1, for some integer ������. LONG ANSWER TYPE QUESTIONS (5 MARKS) Q.16 Show that the cube of any positive integer is of the form 4 ������, 4 ������ + 1 ������������ 4������ + 3, for some integer ������. [56]

Q.17 By using Euclid's division algorithm, find the largest number which when divides 969 and 2059, gives the remainders 9 and 11, respectively. Q.18 If HCF (28, 35 and 343) = 7, find the LCM (28, 35 and 343) Q.19 If HCF of 210 and 55 is expressible in the form 210 × 5 − 55������ , find the value of ������. Q.20 Show that the square of an odd positive integer is of the form 8������ + 1, where ������ is some whole number. CASE STUDY : There are 156, 208 and 260 students in groups A, B and C, respectively. Buses are to be hired to take them for a field trip. Find the minimum number of buses to be hired, if the same number or students should be accommodated in each bus. TRIANGLES VERY SHORT ANSWER TYPE QUESTIONS (1 MARK) Q.1 If D and E are points on the respective sides AB and AC of ∆ABC such that AD = 6 cm, BD = 9 cm, AE = 8 cm, EC = 12 cm, Prove that DE || BC. Q.2 If ∆������������������~∆������������������, ������������ (∆������������������) = 9 , AB = 18 cm and BC = 15 cm, then find PR. ������������ (∆������������������) 4 Q.3 In an isosceles right angled triangle, if the hypotenuse is 5√2 ������������ , then find the length of the sides of the triangle. Q.4 Find the altitude of an equilateral triangle of side 8 cm. Q.5 The areas of two similar triangles are respectively 25������������2 ������������������ 81������������2. Find the ratio of their corresponding sides. SHORT ANSWER TYPE(I) QUESTIONS (2 MARKS) Q.6 In the given figure of ∆ABC, DE || BC. If DC || AP, where point P lies on BC produced, then prove that ������������ = ������������ ������������ ������������ Q.7 PQR and QST are two right angled triangles, right angled at R and T, respectively. Prove that QR × QS = QP × QT. Q.8 In the given figure, if DE || BC, find the ratio of ������������(∆������������������)������������������ ������������(������������������������) Q.9 In ∆������������������, ������������ ⊥ ������������ and ������������2 = ������������ × ������������. Prove that ∆������������������ is a right-angled triangle. Q.10 Or In ∆������������������, ������ ������������ ������ ������������������������������ ������������ ������������, ������������������ℎ ������ℎ������������ ������������ ⊥ ������������. ������������ ������������ . ������������ = ������������2, ������������������������������ ������ℎ������������ < ������������������ = 90°. Two isosceles triangles have equal vertical angles and their areas are in the ratio 36:25. Find the ratio of their corresponding heights. [57]

SHORT ANSWER TYPE(II) QUESTIONS (3 MARKS) Q.11 If a line divides any two sides of a triangle in the same ratio, then the line must be parallel to the third side. Q.12 In ∆ABC, D and E are points on the sides AB and AC respectively, such that DE || BC. If ������������ = 4������ − 3, ������������ = 8������ − 7, ������������ = 3������ − 1 ������������������ ������������ = 5������ − 3, ������������������������ ������ℎ������ ������������������������������ ������������ ������. Q.13 In the given figure, DE || BC. If AD = 3 cm, DB = 4 cm and AE = 6 cm, find EC. Q.14 Diagonals of a trapezium PQRS intersect each other at the point O, PQ || RS and PQ = 3RS. Find the ratio of the areas of ∆POQ and ∆ROS. Q.15 Prove that the area of the equilateral triangle described on the side of an isosceles right-angled triangle is half the area of the equilateral triangle described on its hypotenuse. LONG ANSWER TYPE QUESTIONS (5 MARKS) Q.16 State and prove Thales Theorem. Q.17 In the given figure, ∆ABC and ∆DBC have same base BC and lie on the same side of BC. If PQ || BA and PR || BD , the prove that QR || AD. Q.18 In ∆ABC, D and E are points on the sides AB and AC respectively, such that DE || BC. If AD = 4������ − 3, ������������ = 8������ − 7, ������������ = 3������ − 1 ������������������ ������������ = 5������ − 3, find the value of ������. Q.19 In the given figure, AB || PQ || CD, ������������ = ������ units, ������������ = ������ units and ������������ = ������ units. Prove that 1+ 1= 1 ������ ������ ������ Q.20 In the given figure, the line segment XY is parallel to side AC of ∆ABC and it divides the triangle into two parts of equal areas. Find the ratio ������������ . ������������ [58]

Case Study : A girl of height 90 cm is walking away from the base of a lamp-post at a speed of 1.2 m/s. If the lamp is 3.6m above the ground, then find the length of her shadow after 4s. INTRODUCTION OF TRIGONOMETRY VERY SHORT ANSWER TYPE QUESTIONS (1 MARK) Q.1 If tan(3������ + 30°) = 1, find the value of ������ Q.2 What happens to value of ������������������������ when ������ increases from 0° to 90°. Q.3 In right angled ∆ABC, right angles at B, AB = 5 cm and <ACB = 30°. Determine the length of the sides BC and AC. Q.4 Find the value of (tan 1° tan 2° tan 3° ...... tan 89° ) Q.5 Evaluate ������������������230° + ������������������245° − 1 ������������������260° 3 SHORT ANSWER TYPE(I) QUESTIONS (2 MARKS) Q.6 If tan ������ =4, find the other trigonometric ratios of <A. 3 Q.7 Prove that cot A + tan A = sec A cosec A. Q.8 Evaluate ������������������ 70° + ������������������������������ 36° - 2 ������������������ 43° ������������������������������ 47° ������������������ 20° ������������������ 54° tan 10° tan 40° tan 50° tan 80° Q.9 If cos(������ − ������) = cos ������ cos ������ + sin ������ sin ������, find the value of (i) ������������������ 15° (ii) ������������������ 75° Q.10 In the following figure, ∆PQR is right angled at Q, PQ = 3 cm and PR = 6 cm. Determine < QPR and < PRQ. SHORT ANSWER TYPE(II) QUESTIONS (3 MARKS) Q.11 In ∆PQR right angled at Q, QR = 3 cm and PR – PQ = 1 cm. Determine the values of sin R, cos R and tan R. Q.12 If sin(������ − ������) = 1 , cos(������ + ������) = 1 , 0° < ������ + ������ ≤ 90° , ������ > 22 ������, ������������������������ ������ℎ������ ������������������������������ ������������ ������ ������������������ ������. Q.13 Prove the trigonometric identity √ ������������������������������ ������ – 1 + √������������������������������ ������ + 1 = 2 sec ������. ������ + 1 ������������������������������ ������������������������������ ������ – 1 [59]

Q.14 If sec 5A = cosec (A + 30°), where 5A is an acute angle, then find the value of A. Q.15 Evaluate 8√3 cosec2 300 sin 600 cos 600 cos2 450 sin 450 tan 300 cosec3 450 LONG ANSWER TYPE QUESTIONS (5 MARKS) Q.16 If ������ ������������������������ − ������ ������������������ ������ = ������ ������������������ ������ sin ������ + ������������������������������ = ������ , ������������������������������ ������ℎ������������ ������2 + ������2 = ������2 + ������2 Q.17 If ������������������������ + ������������������ ������ = ������ ������������������ ������������������������ − ������������������ ������ = ������ ������ℎ������������ ������ℎ������������ ������ℎ������������ (������2 − ������2)2 = 16 ������������ or (������2 − ������2) = 4√������������ . Q.18 Prove that ������������������ ������ + ������������������ ������ + ������������������ ������− ������������������ ������ = 2 ������������������ ������− ������������������ ������ ������������������2 ������− ������������������2 ������ ������������������ ������+ ������������������ ������ Q.19 Find the acute angles A and B, if sin (A + 2B) = √3 and cos (A + 4B) = 00, ������ > ������ 2 Q.20 If ������ cot ������ = ������ , ������������������������ ������ℎ������ ������������������������������ ������������ ������ ������������������ ������− ������ ������������������ ������ ������ ������������������ ������ + ������ ������������������ ������ CONSTRUCTIONS SHORT ANSWER TYPE QUESTIONS (2/3 MARKS) Q.1 Draw a line segment AB = 8 cm and divide it internally in the ratio 3:2 and also justify it. Q.2 Construct a triangle similar to given ∆ABC, where AB = 6 cm, BC = 7 cm and AC = 8 cm, with its sides equal to ¾ of the corresponding sides of ∆ABC. Also, justify the construction. Q.3 Construct a triangle similar to given ∆ABC whose sides are 6 cm, 7 cm and 8 cm, with its sides equal to 5 of the corresponding sides of ∆ABC. 3 Q.4 Draw a circle of radius 5 cm. Take a point P on it. Without using the centre of the circle, draw a tangent to the circle at point P. Q.5 Draw a circle of radius 1 cm. From a point P, 2.2 cm apart from the centre of the circle, draw tangents to the circle. Also, justify the construction. LONG ANSWER TYPE QUESTIONS (5 MARKS) Q.6 Construct a tangent to a circle of radius 1.8 cm from a point on the concentric circle of radius 1.8 cm from a point on the concentric circle of radius 2.8 cm and measure its length. Also, verify the measurement by actual calculation. [60]

Q.7 Draw a circle with the help of circular solid ring. Construct a pair of tangents from a point P outside the circle. Q.8 Draw a circle of radius 2.8 cm. From an external point P, draw tangents to the circle without using the centre of the circle. Q.9 Draw a pair of tangents to a circle of radius 3 cm which are inclined to each other at an angle of 450. Q.10 Draw a circle of diameter 3.5 cm. Let there be a point P outside circle. Draw tangents to circle from P without using the centre of circle. [61]

SCIENCE (SUBJECT CODE: 086) [62]

CHEMISTRY CHAPTER: CHEMICAL REACTIONS AND EQUATIONS MULTIPLE CHOICE QUESTIONS 1. 2 PbO(s) + C (s) → 2Pb(s) + CO2 (g) Which of the following statements are correct for the above? a) Lead is reduced. b) Carbon dioxide is oxidized. c) Carbon is oxidized. d) Lead oxide is reduced. i) (a) and (b) ii) (a) and (c) iii) (a) , (b) , and (c) d) all. 2. Balance the following chemical equations including the physical states. a) C6H12O6 → C2H5OH + CO2 b) Fe + O2 → Fe2O3 c) NH3 + Cl2 → N2H4+NH4Cl d) Na + H2O → NaOH +H2 3. Balance the chemical equation by including the physical states of the substances for the following reactions. a) Barium chloride and sodium sulphate aqueous solutions react to give insoluble Barium sulphate and aqueous solution of sodium chloride. b) Sodium hydroxide reacts with hydrochloric acid to produce sodium chloride and water. c) Zinc pieces react with dilute hydrochloric acid to liberate hydrogen gas and forms zinc chloride 4. Which of the following is not a physical change? (a) Boiling of water to give water vapour (b) Melting of ice to give water (c) Dissolution of salt in water (d) Combustion of Liquefied Petroleum Gas (LPG) 5. The following reaction is an example of a 4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(g) [63]

(i) displacement reaction (ii) combination reaction (iii) redox reaction (iv) neutralisation reaction (a) (i) and (iv) (b) (ii) and (iii) (c) (i) and (iii) (d) (iii) and (iv) 6. Which of the following statements about the given reaction are correct? 3Fe(s) + 4H2O(g) → Fe3O4(s) + 4H2(g) (i) Iron metal is getting oxidised (ii) Water is getting reduced (iii) Water is acting as reducing agent (iv) Water is acting as oxidising agent (a) (i) , (ii) and (iii) (b) (iii) and (iv) (c) (i) , (ii) and (iv) (d) (ii) and (iv) 7. Which of the following are exothermic processes? (i) Reaction of water with quick lime (ii) Dilution of an acid (iii) Evaporation of water (iv) Sublimation of camphor (crystals) (a) (i) and (ii) (b) (ii) and (iii) (c) (i) and (iv) (d) (iii) and (iv) 8. Three beakers labelled as A, B and C each containing 25 mL of water were taken. A small amount of NaOH, anhydrous CuSO4 and NaCl were added to the beakers A, B and C respectively. It was observed that there was an increase in the temperature of the solutions contained in beakers A and B, whereas in case of beaker C, the temperature of the solution falls. Which one of the following statement(s) is(are) correct? (i) In beakers A and B, exothermic process has occurred. (ii) In beakers A and B, endothermic process has occurred. (iii) In beaker C exothermic process has occurred. (iv) In beaker C endothermic process has occurred. (a) (i) only (b) (ii) only (c) (i) and (iv) [64]

(d) (ii) and (iii) 9. A dilute ferrous sulphate solution was gradually added to the beaker containing acidified permanganate solution. The light purple colour of the solution fades and finally disappears. Which of the following is the correct explanation for the observation? (a) KMnO4 is an oxidising agent, it oxidises FeSO4 (b) FeSO4 acts as an oxidising agent and oxidises KMnO4 (c) The colour disappears due to dilution; no reaction is involved (d) KMnO4 is an unstable compound and decomposes in presence of FeSO4 to a colourless compound. 10. Which among the following is(are) double displacement reaction(s)? (i) Pb + CuCl2 → PbCl2 + Cu (ii) Na2SO4 + BaCl2 → BaSO4 + 2NaCl (iii) C + O2 → CO2 (iv) CH4 + 2O2 → CO2 + 2H2O (a) (i) and (iv) (b) (ii) only (c) (i) and (ii) (d) (iii) and (iv) 11. Which among the following statement(s) is(are) true? Exposure of silver chloride to sunlight for a long duration turns grey due to (i) the formation of silver by decomposition of silver chloride (ii) sublimation of silver chloride (iii) decomposition of chlorine gas from silver chloride (iv) oxidation of silver chloride (a) (i) only (b) (i) and (iii) (c) (ii) and (iii) (d) (iv) only 12. Solid calcium oxide reacts vigorously with water to form calcium hydroxide accompanied by liberation of heat. This process is called slaking of lime. Calcium hydroxide dissolves in water to form [65]

its solution called lime water. Which among the following is (are) true about slaking of lime and the solution formed? (i) It is an endothermic reaction (ii) It is an exothermic reaction (iii) The pH of the resulting solution will be more than seven (iv) The pH of the resulting solution will be less than seven (a) (i) and (ii) (b) (ii) and (iii) (c) (i) and (iv) (d) (iii) and (iv) 13. Barium chloride on reacting with ammonium sulphate forms barium sulphate and ammonium chloride. Which of the following correctly represents the type of the reaction involved? (i) Displacement reaction (ii) Precipitation reaction (iii) Combination reaction (iv) Double displacement reaction (a) (i) only (b) (ii) only (c) (iv) only (d) (ii) and (iv) 14. Electrolysis of water is a decomposition reaction. The mole ratio of hydrogen and oxygen gases liberated during electrolysis of water is (a) 1:1 (b) 2:1 (c) 4:1 (d) 1:2 15. Which of the following is(are) an endothermic process(es) ? (i) Dilution of sulphuric acid (ii) Sublimation of dry ice (iii) Condensation of water vapours (iv) Evaporation of water (a) (i) and (iii) (b) (ii) only (c) (iii) only (d) (ii) and (iv) [66]

16. In the double displacement reaction between aqueous potassium iodide and aqueous lead nitrate, a yellow precipitate of lead iodide is formed. While performing the activity if lead nitrate is not available, which of the following can be used in place of lead nitrate? (a) Lead sulphate (insoluble) (b) Lead acetate (c) Ammonium nitrate (d) Potassium sulphate 17. Which of the following gases can be used for storage of fresh sample of an oil for a long time? (a) Carbon dioxide or oxygen (b) Nitrogen or oxygen (c) Carbon dioxide or helium (d) Helium or nitrogen 18. The following reaction is used for the preparation of oxygen gas in the laboratory. Which of the following statement(s) is(are) correct about the reaction? (a) It is a decomposition reaction and endothermic in nature (b) It is a combination reaction (c) It is a decomposition reaction and accompanied by release of heat (d) It is a photochemical decomposition reaction and exothermic in nature 19. Which one of the following processes involve chemical reactions? (a) Storing of oxygen gas under pressure in a gas cylinder (b) Liquefaction of air (c) Keeping petrol in a china dish in the open (d) Heating copper wire in presence of air at high temperature 20. In which of the following chemical equations, the abbreviations represent the correct states of the reactants and products involved at reaction temperature? (a) 2H2(l) + O2(l) → 2H2O(g) (b) 2H2(g) + O2(l) → 2H2O(l) (c) 2H2(g) + O2(g) → 2H2O(l) (d) 2H2(g) + O2(g) → 2H2O(g) 21.Which of the following reactions involves the combination of two elements :- (a) CaO + CO2 -> CaCO3 [67]

(b) 4Na + O2 -> 2Na2O (c) SO2 +( 1/2) O2 -> SO3 (d) NH3 + HCI -> NH4CI 22.When hydrogen sulphide gas is passed through a blue solution of copper sulphate, a black precipitate of copper sulphate is obtained and the sulphuric acid so formed remains in the solution. The reaction is an example of:- (a) A combination reaction (b) A displacement reaction (c) A decomposition reaction (d) A double decomposition reaction 23.A student added dilute HCI to a test tube containing zinc granules and made following observations:- (a) The zinc surface became dull and black (b) A gas evolved which burnt with a pop sound (c) The solution remained colorless (d) The solution becomes green in color. 24.A dilute solution of sodium carbonate was added to two test tubes one containing dilute HCI (A) and the other containing dilute NaOH (B) . the correct observation was:- (a) A brown colored gas liberated in test tube A (b) A brown colored gas liberated in test tube B (c) A colorless gas liberated in test tube A (d) A colorless gas liberated in test tube B 25.A balanced chemical equation is in accordance with (a) Avogadro’s law (b) Law of multiple proportion (c) Law of conservation of mass (d) Law of gaseous volumes 26.The equation Cu + xHNO3 -> Cu(NO3) 2 + yNO2 + 2H2O The values of x and y are [68]

(a) 3 and 5 (b) 8 and 6 (c) 4 and 2 (d) 7 and 1 27. When the gases sulphur dioxide and hydrogen sulphide mix in the presence of water, the reaction is SO2 + 2H2S → 2H2O + 3S. here hydrogen sulphide is acting as (a) An oxidizing agent (b) A reducing agent (c) A dehydrating agent (d) A catalyst ASSERTION REASONING TYPE QUESTIONS Directions (Q. Nos. 1-8) In the following questions a statement of Assertion is followed by a statement of Reason. Mark the correct choice as (a) If both Assertion and Reason are true and Reason is the correct explanation of Assertion. (b) If both Assertion and Reason are true but Reason is not the correct explanation of Assertion. (c) If Assertion is true but Reason is false. (d) If Reason is true but Assertion is false. (e) If both Assertion and Reason are false. Q1. Assertion: Chemical reaction changes the physical and chemical state of a substance. Reason: When electric current is passed through water (liquid) , it decomposes to produce hydrogen and oxygen gases. Q2. Assertion: In a balanced chemical equation, total mass of each element towards reactant side= total mass of the same element towards product side. Reason: Mass can neither be created nor destroyed during a chemical change. Q3. Assertion: When calcium carbonate is heated, it decomposes to give calcium oxide and carbon dioxide. [69]

Reason: The decomposition reaction takes place on application of heat, therefore, its and endothermic reaction. Q4. Assertion: Chips manufacturers usually flush bags of chips with gas such as nitrogen to prevent the chips from getting oxidised. Reason: This increase the taste of the chips and helps in their digestion. Q5. Assertion: Rusting of iron metal is the most common form of corrosion. Reason: The effect of rusting of iron can be reversed if they are left open in sunlight. Q6. Assertion: a reaction in which a single product is formed from two or more reactants is known as combination reaction. Reason: Reaction between quick lime and water is a precipitation reaction. Q7. Assertion:The following reaction is an example of oxidation only ZnO (s) + C (s) heat ⎯⎯⎯→ Zn (s) + CO (g) Reason:Zn is the substance that is oxidized. Q8. Assertion: When two different ions are exchanged between two reactants double displacement reaction occurs Reason: Precipitation reactions are the result of ion exchange between two substances, producing insoluble salts. VERY SHORT ANSWER QUESTIONS (1 MARK) Q1. Write a chemical equation when magnesium metal reacts with aqueous hydrochloric acid to produce a solution of magnesium chloride and hydrogen gas. Q2. Can a combination reaction be redox reaction? Q3. Why do we apply paint on iron articles? Q4. What are the different types of reactions? Q5. What is a decomposition rection? Give example. Q6. Define displacement reaction. Q7. What happens when sodium reacts with water? Q 8. Write the chemical equation and name the reaction when a solution of sodium chloride is mixed with a solution of silver nitrate and a white precipitate of silver chloride is formed. Q 9. Why does the color of copper sulphate solution change, when an iron nail is dipped in it? Q10. Why is photosynthesis considered as an endothermic reaction? Q11. Potassium chlorate (KClO3) on heating forms potassium chloride and oxygen. Write a balanced equation for this reaction. [70]

Q12. Give an example of a chemical reaction characterized the change in temperature. Q13. Hydrogen being a highly inflammable gas and oxygen being a supporter of combustion, yet water which is a compound made up of hydrogen and oxygen is used to extinguish fire. Why? Q14. To balance a chemical equation, can we change the formula of either reactants or products? Q15. Why should a magnesium ribbon be cleaned before burning in air? Q16. If an of the following reactions occurs spontaneously, write the balanced net ionic equation. If not, write no reaction a) Pb + Zn2+ → Pb2+ + Zn b) Fe + H+ → Fe2+ + H2 c) Cu + Ag+ → Cu2+ + Ag d) Cr + Zn2+ → Cr3+ + Zn Q17. Nickel (II) nitrate is prepared by heating nickel metal with liquid dinitrogen tetroxide. In addition to the nitrate, gaseous nitrogen monoxide is formed. Write the balanced equation. Q18. Why is the amount of gas collected in one of the test tubes in electrolysis of water double of the amount collected in the other? Name this gas. Q19. Write a balanced chemical equation with state symbols for the following reactions: - a. Solution of barium chloride and sodium sulphate in water react to give insoluble barium sulphate and the solution of sodium chloride. b. Sodium hydroxide solution (in water) reacts with hydrochloric acid solution (in water) to produce sodium chloride solution and water. SHORT ANSWER QUESTIONS (2-3MARKS) Q1. What is the ratio of number of moles of reactants to the number of moles of products in the equation? H2S (g) + SO2 (g) -> S (s) + H2O (liq) Q2. In the refining of silver, the recovery of silver from silver nitrate solution involved displacement by copper metal. Write down the reaction involved. Q3. Translate the following statements into chemical equations and then balance them. a) Hydrogen gas combines with nitrogen to form ammonia b) Hydrogen Sulphide gas burns in air to give water and sulfur dioxide. c) Barium chloride reacts with aluminum sulphate to give aluminum chloride and a precipitate of barium sulphate. d) Potassium metal reacts with water to give potassium hydroxide and hydrogen gas [71]

Q4. Balance the following chemical equations:- a) HNO3 + Ca(OH) 2 -> Ca (NO3) 2 + H2O b) NaOH + H2SO4 -> Na2SO4 + H2O c) NaCI + AgNO3 -> AgCI + NaNO3 d) BaCI2 + H2SO4 -> BaSO4 + HCI Q5. Write the balanced chemical equation of the following and identify the type of reaction in each case: a) Potassium bromide (aq) + Barium iodide (s) b) Zinc carbonate (s) -> Zinc oxide (s) + Carbon dioxide (g) c) Magnesium (s) + hydrochloric acid (aq) ->Magnesium chloride (aq) + Hydrogen (g) Q6. Balance the following chemical reaction: a) NH4NO3 -> N2O + H2O b) P4O10 + H2O -> H3PO4 c) HIO3 -> I2O5 + H2O d) As + Cl2 -> AsCl5 Q7. Balance the chemical equations for the following important industrial processes: a) Molecular nitrogen and hydrogen combine to give ammonia. b) Molecular hydrogen and carbon monoxide react to form methanol (CH3OH). c) CaO + C ->CO + CaC2 d) C2H4 + O2+ HCl -> C2H4Cl2 + H2O Q8. Here are some reactions involving water. Balance the equations: a) Ca(OH) 2 + H3PO4 -> H2O + Ca3(PO4) 2 b) Na2O2 + H2O -> NaOH + O2 c) BF3 + H2O -> HF + H3BO3 d) NH3 + CuO -> Cu + N2 + H2O Q9. Represent each of the following word equations with a balanced chemical equation. a) Disilane gas (Si2H6) undergoes combustion to form solid silicon dioxide and water. b) Solid aluminum hydride is formed by a combination reaction of its two elements. c) When solid calcium bi sulfate is heated, it decomposes to solid calcium oxide, sulfur dioxide gas, and water. [72]

Q10. A solution of AgNO3 is mixed with a solution of K2S. write the molecular, total ionic and net ionic equations illustrating the reaction. Q11.You might have noted that when copper powder is heated in a china dish, the surface of copper powder becomes coated with a black colour substance. a) How has this black coloured substance formed? b) What is that black substance? c) Write the chemical equation of the reaction that takes place. Q12. Consider the following chemical reaction X + Barium chloride——–> Y + Sodium chloride (White ppt) a) Identify ‘X’ and ‘Y’ b) The type of reaction Q13. State the type of chemical reactions and chemical equations that take place in the following: a) Magnesium wire is burnt in air. b) Electric current is passed through water. c) Ammonia and hydrogen chloride gases are mixed. Q14. What type of chemical reactions take place when? a) Limestone is heating? b) A magnesium wire is burnt in air? c) Electricity is passed through water? d) Ammonia and hydrogen chloride are mixed? e) Silver bromide is exposed to sunlight? Q15. Express the following reactions in the form of chemical equations and balance them. Make an equation as informative as you can. Also mention the type of reaction: - a) When solid mercury (II) oxide is heated, liquid mercury and oxygen gas are produced. b) Ethyne (C2H2) gas burns in oxygen to form carbon dioxide and water along with evolution of heat. c) Phosphorus burns in oxygen to form phosphorus pentaoxide. d) Magnesium ribbon is burnt in a jar containing nitrogen gas when a white powder of magnesium nitrite is obtained. e) Marble dissolves in HCL acid to give calcium chloride; water and carbon dioxide. Q16.Why are halides (chloride, bromide, and iodide) of silver kept in dark brown or black bottles? Q17. Name the following and give equations for these reactions: a) A white solid, which when heated, leaves behind a yellow solid and gives CO2. b) A bluish green powder, on heating, leaves behind a black solid and gives CO2. [73]

c) A colorless solid produces a yellow solid when hot and a white solid when cold and gives a reddish- brown gas. Give equations for each. LONG ANSWER QUESTIONS (5 MARKS) Q1). Write chemical reaction for these a) Treating dilute sulphuric acid with sodium hydroxide solution b) Heating ammonium chloride c) Changing ammonium chloride into sodium and chlorine d) Heating a mixture of iron and sulfur e) Passing chlorine through a solution of potassium bromide Q2). When a strip of red-brown metal X is placed in a colourless salt solution YNO3 then metal Y is set free and a blue coloured salt solution X(NO3) 2 is formed. The liberated metal Y forms a shining white deposit on the strip of metal X. a) What do you think metal X is? b) Name the salt YNO3. c) What could be metal Y? d) Name the salt X(NO3)2. e) What type of reaction takes place between metal X and salt solution YNO3? Q3). When a black metal compound XO is heated with a colourless gas Y2, then metal X and another compound Y2O are formed. Metal X is red-brown in colour which does not react with dilute acids at all. Gas Y2 can be prepared by the action of a dilute acid on any active metal. The compound Y2O is a liquid at room temperature which can turn anhydrous copper sulphate blue. a) What do you think is metal X? b) What could be gas Y2? c) What is compound XO? d) What is compound Y2O? e) Write the chemical equation of the reaction which takes place on heating XO with Y2. f) What type of chemical reaction is illustrated in the above equation? Q4). In the electrolysis of water, a) Name the gas collected at the cathode and anode. b) Why is the volume of gas collected at one electrode double the other? c) Why are a few drops of dil. H2SO4 added to the water? Q5) a) Mention three ways by which a usual chemical equation can be made more informative. b) Describe an activity to observe what happens when quick lime is added to water taken in a beaker. State two important observations and name the type of reaction taking place. [74]

Q6) a) What is meant by skeletal chemical equation? What does it represent? Using the equation for electrolytic decomposition of water, differentiate between a skeletal chemical equation and a balanced chemical equation. b) Write the balanced chemical equation for the following reaction: (i) Phosphorus burns in presence of chlorine to form phosphorus pentachloride. (ii) Burning of natural gas. (iii) The process of respiration. Q7) A metal nitrate ‘A’ on heating gives yellowish brown coloured metal oxide along with brown gas ‘B’ and a colourless gas ‘C’. Aqueous solution of ‘A’ on reaction with potassium iodide forms a yellow precipitate of compound ‘D’. Identify ‘A, B, C, D’. Also identify the types of both the reactions. Metal present in ‘A’ is used in alloy which is used for soldering purposes. Q8) (a) Write one example for each of decomposition reaction carried out with help of (i) Electricity (ii) Heat (iii) Light (b) Which of the following statements is correct and why copper can displace silver from silver nitrate and silver can displace copper from copper sulphate solution. Q9) (a) The following diagram displays a chemical reaction. Observe carefully and answer the following questions i. Identify the type of chemical reaction that will take place and define it. How will the colour of the salt change? ii. Write the chemical equation of the reaction that takes place. iii. Mention one commercial use of this salt. (b) Write the chemical equation of the reaction in which the following changes have taken place with an example of each: (i) Change in colour (ii) Change in temperature Q10) A metal salt MX when exposed to light splits up to form metal M and a gas X2. Metal M is used in making ornaments whereas gas X2 is used in making bleaching powder. The salt MX is itself used in black and white photography. (a) What do you think metal M is ? (b) What could be gas X2 ? (c) Name the metal salt MX. (d) Name any two salt solutions which on mixing together can produce a precipitate of salt MX. (e) What type of chemical reaction takes place when salt MX is exposed to light ? Write the equation of the reaction. [75]

PASSAGE BASED QUESTIONS Read the following passage and answer the questions that follow: Q1) Chemical Reactions Power Cells: Two important processes that power much of all life on Earth are photosynthesis, which converts sunlight into the six-carbon sugar glucose, and cellular respiration, which converts glucose into usable energy. Both these essential reactions are, at their core, a pair of complementary chemical reactions. Photosynthetic organisms use the energy from sunlight to convert carbon dioxide and water into sugar and molecular oxygen. Cellular respiration is then used by all aerobic organisms to break down that sugar—whether they made it or consumed it—in the presence of oxygen to produce energy for all of their basic needs. i) Write a balanced chemical equation for the process of photosynthesis giving the physical states of all the substances involved and the conditions of the reaction. ii) What do you understand by exothermic and endothermic reactions? iii) Give one example of an exothermic reaction and one of an endothermic reaction. iv) Why is photosynthesis considered an endothermic reaction? Q2) Redox reactions are reactions in which one species is reduced and another is oxidized. Therefore the oxidation state of the species involved must change. These reactions are important for a number of applications, including energy storage devices (batteries) , photographic processing, and energy production and utilization in living systems including humans. Historically, the term \"oxidation\" was used because the redox reactions that were first systematically investigated took place in oxygen, with oxygen being reduced and the other species being oxidized, hence the term oxidation reaction. However, it was later realized that this case (oxidation reactions involving oxygen) was just one possible scenario. a) What is a redox reaction? Explain with an example. (b) When a magnesium ribbon burns in air with a dazzling flame and forms a white ash, is magnesium oxidised or reduced? Why? (c) In the reaction represented by the equation: MnO2 + 4Hl ———–> MnCl2 + 2H2O + Cl2 1. name the substance oxidised. 2. name the oxidising agent. 3. name the substance reduced. 4. name the reducing agent. Q3) Photolysis (also called photodecomposition) is a chemical reaction in which an inorganic chemical (or an organic chemical) is broken down by photons and is the interaction of one or more photons with one target molecule. The photolysis reaction is not limited to the effects of visible light but any photon with sufficient energy can cause the chemical transformation of the inorganic bonds of a chemical. [76]

(a) Why are decomposition reactions called the opposite of combination reactions? Explain with equations of these reactions. (b) What happens when silver chloride is exposed to sunlight? (c) Write a chemical equation for this reaction. Also give one use of such a reaction CHAPTER: ACIDS, BASES AND SALTS MUTIPLE CHOICE QUESTIONS: - Q1. pH paper is separately dipped into 2 different solutions X and Y. Colour of pH paper turned pale green in X and blue in Y. X and Y are most probably: (NTSE) (a) X — water, Y — NaOH (b) X — NaOH, Y — H 2 O (c) X — HCl, Y — NaOH (d) X — NaOH, Y — HCl Q2. Ammonium chloride is a salt of: (NTSE) (a) Weak Acid and Weak Base (b) Weak Acid and Strong Base (c) Strong Acid and Strong Base (d) Strong Acid and Weak Base Q3.A metal carbonate (X) on thermal decomposition produces a solid residue and a gas (Y). When (Y) is passed through aqueous solution of another substance (Z) gives back X. The compounds X, Y and Z respectively are (NTSE) (a) Ca(OH)2, CaC03, CO2 (b) Ca(HCO3)2, Ca(OH)2, CaCO3 (c) CaCO3, CO2, Ca(OH)2 (d) CaCO3, CO2, Ca(HCO3)2 Q4. Metallic oxides are ___________ in nature, but non-metallic oxides are ____________ in nature. The information in which alternative completes the given statement? (NTSE) [77]

(a) neutral, acidic (b) acidic, basic (c) basic, neutral (d) basic, acidic PASSAGE BASED QUESTIONS: - Q5. Read the following passage and answer the questions: - The process of dissolving an acid or a base in water is a highly exothermic one. Care must be taken while mixing concentrated nitric acid or sulphuric acid with water. The acid must always be added slowly to water with constant stirring. If water is added to a concentrated acid, the heat generated may cause the mixture to splash out and cause burns. The glass container may also break due to excessive local heating. Look out for the warning sign (shown in Fig. 2.5) on the can of concentrated sulphuric acid and on the bottle of sodium hydroxide pellets. Mixing an acid or base with water results in decrease in the concentration of ions (H3O+/OH–(H3O+/OH–) per unit volume. Such a process is called dilution and the acid or the base is said to be diluted. 5(i) What happens when a solution of an acid is mixed with a solution of a base in a test tube? (i) Temperature of the solution decreases (ii) Temperature of the solution increases (in) Temperature of the solution remains the same (iv) Salt formation takes place (a) (i) and (iv) (b) (i) and (iii) (c) (ii) only (d) (ii) and (iv) 5(ii) In terms of acidic strength, which one of the following is in the correct increasing order? (a) Water < Acetic acid < Hydrochloric acid (b) Water < Hydrochloric acid < Acetic acid [78]

(c) Acetic acid < Water < Hydrochloric acid (d) Hydrochloric acid < Water < Acetic acid 5(iii) Dilution of an acid or base is:- (a) Decrease in concentration of hydronium/hydroxyl ions per unit volume (b) Increase in concentration of hydronium/hydroxyl ions per unit volume (c) No change in concentration of hydronium/hydroxyl ions per unit volume (d) None of the above 5(iv) If a few drops of a concentrated acid accidentally spills over the hand of a student, what should be done? (a) Wash the hand with saline solution. (b) Wash the hand immediately with plenty of water and apply a paste of sodium hydrogen carbonate. (c) After washing with plenty of water and apply solution of sodium hydroxide on the hand. (d) Neutralise the acid with a strong alkali. Q6. Which of the following statement is wrong? (NSO) (a) A weak acid dissociate incompletely (b) The solution of a salt of a weak acid and strong base is alkaline. (c) The solution of a salt of a weak acid and a strong base is neutral (d) A monobasic acid cannot form an acid salt Q7. Choose the correct option from the following:- (NSO) (a) Universal indicator are class of compound, that shows distinctly different colours in acidic and alkaline solution (b) Acid-Base indicator show different colours at different pH values (c) A universal indicator are class of compounds which shows different colours at different pH values (d) Methyl orange is a universal indicator Q8. Zinc granules on treating with an acid X, form the zinc sulphate (ZnSO4) salt along with the evolution of a gas Y which burns with a pop sound when brought near to a burning candle. Identify the acid X and gas evolved Y. (NSO) [79]

(a) X- Sulphuric acid and Y- Oxygen gas (b) X- Hydrochloric acid and Y- Oxygen gas (c) X- Sulphuric acid and Y- Hydrogen gas (d) X- Hydrochloric acid and Y- Hydrogen gas Q9. The figure given below represents the experiment carried out between conc. sulphuric acid and sodium chloride, which react with each other to form HCl gas. Blue litmus paper is brought near the mouth of the delivery tube to check the presence of HCl acid but no change is observed in the color of litmus paper because: (a) The litmus paper used is dry (b) The litmus paper used is moist (c) Blue litmus paper does not change its color with an acid (d) The litmus paper is kept very close to the mouth of the delivery tube Q10.Common salt besides being used in the kitchen can also be used as the raw material for making: (i) washing soda (ii) bleaching powder (iii) baking soda (iv) slaked lime (a) (i) and (ii) (b) (i) , (ii) and (iv) (c) (i) and (iii) (d) (i) , (iii) and (iv) Q11 to Q 15. ASSERTION REASONING QUESTIONS:- Read the statements carefully and choose the correct alternative from the following: (a) Both the Assertion and the Reason are correct and the Reason is the correct explanation of the Assertion. (b) The Assertion and the Reason are correct but the Reason is not the correct explanation of the Assertion. (c) Assertion is true but the Reason is false. (d) The statement of the Assertion is false but the Reason is true. [80]

Q11.Assertion: Universal indicator gives green colour with distilled water. Reason: pH of distilled water is 7 and it is neutral and universal indicator gives green colour with neutral solution. Q12. Assertion:- Phenolphthalein gives pink colour in basic solution. Reason:- Phenolphthalein is an natural indicator Q13. Assertion: - Aqueous solutions of glucose and alcohol do not show acidic character. Reason:- Aqueous solutions of glucose and alcohol do not give H+ ions. Q14.Assertion: H2CO3 is a strong acid. Reason: A strong acid dissociates completely or almost completely in water. Q15.Assertion: Baking soda creates acidity in the stomach. Reason: Baking soda is alkaline in nature. Q16. MATCH THE FOLLOWING:- A Plaster of Paris i CaSO4.2H2O B Bleaching Powder ii CaO C Washing Soda iii CaSO4.1/2H2O D Gypsum iv Na2CO3.10H2O E Slaked Lime v Ca(OH)2 F Quick Lime vi CaOCl2 Q17. FILL IN THE BLANKS: - a) Acid turns .........litmus solution........ b) pH of basic solution is always...............than 7. c) .............is the fixed number of water molecules chemically attached to each formula unit of a salt in its crystalline form. d) ......is one of the raw materials used for the production of baking soda. [81]

e) The salts of strong acid and weak base are.....with pH value ....than 7. f) Use of mild base like ......on the bee stung area gives relief. Q18. SHORT ANSWER TYPE QUESTIONS: - a) Name the compound used for softening hard water. b) What happens when baking soda is heated? c) Why does a milkman add a small amount of baking soda to fresh milk to shift the pH of fresh milk from 6 to slightly alkaline? d) A calcium compound which is a yellow white powder is used as a disinfectant and also in textile industries. Name the compound. Which gas is released when this compound is left exposed to air. e) Neeta had baked a cake, which is bitter in taste? why? Q19. LONG ANSWER QUESTIONS: - a) (i) Four samples A, B, C and D change the colour of pH paper or solution to Green, Reddish-pink, Blue and Orange. Their pH was recorded as 7, 2, 10.5 & 6 respectively. Which of the samples has the highest amount of Hydrogen ion concentration? Arrange the four samples in the decreasing order of their pH. (ii) Rahul found that the Plaster of Paris, which he stored in a container, has become very hard and lost its binding nature. What is the reason for this? Also, write a chemical equation to represent the reaction taking place. (iii) Give any one use of Plaster of Paris other than for plastering or smoothening of walls. b) What happens when: - (i) Solid sodium hydrogen carbonate is heated, (ii) Chlorine gas is passed through dry slaked lime, (iii) Gypsum is heated to a temperature of 373 K? c) When a gas is passé through saturated solution of ammonical brine, two compounds ‘X’ and ‘Y’ are formed. ’Y’ is used as an antacid and decompose to form another solid ‘Z’. Identify ‘X’,’Y’ and ‘Z’ and give balanced chemical equations for all the reactions involved. [82]

CHAPTER: METAL AND NON-METALS MULTIPLE CHOICE QUESTIONS (NTSE) 1. Al2O3 + 2NaOH → …… + H2O (a) Al(OH) 3 (b) Na2O (c) NaAlO2 (d) AlNaO2 2. Which of the following pairs will give dis-placement reactions? (a) FeSO4 solution and Copper metal (b) AgNO3 solution and Copper metal (c) CuSO4 solution and Silver metal (d) NaCl solution and Copper metal 3. When a metal is added to dilute HCI solution, there is no evolution of Hydrogen gas. Metal is (a) K (b) Na (c) Ag (d) Zn 4.The electronic configuration of three elements X, Y and Z are as follows: X = 2, 4, Y = 2, 7, Z = 2,1 Which two elements will combine to form an ionic compound and write the correct formula, (NSO) (a) X2Y (b) YZ (c) XZ3 (d) Y2Z 5. Which of the following non-metal is lustrous? (NSO) (a) Sulphur (b) Oxygen (c) Nitrogen (d) Iodine [83]

6.An element X is soft and can be cut with a knife. This is very reactive to air and cannot be kept open in air. It reacts vigorously with water. Identify the element from the following. (NTSE) (a) Mg (b) Na (c) P (d) Ca 7.Reaction between X and Y forms compound Z. X loses electron and Y gains electron. Which of the following properties is not shown by Z? (a) Has high melting point (b) Has low melting point (c) Conducts electricity in molten state (d) Occurs as solid 8.What happens when calcium is treated with water? (NSO) (i) It does not react with water. (ii) It reacts violently with water. (iii) It reacts less violently with water. (iv) Bubbles of hydrogen gas formed stick to the surface of calcium. 9.Which one of the following four metals would be displaced from the solution of its salts by other three metals? (a) Mg (b) Ag (c) Zn (d) Cu 10.Which of the following statement is incorrect? (a) Most non-metals produce acidic oxides when dissolve in water. (b) Platinum, is an allotrope of carbon, is the hardest natural substance known and has a very high melting and boiling point. (c) Alkali metals (lithium, sodium, potassium) are so soft that they can be cut with a knife. (d) All metals except mercury exist as solids at room temperature. Q11 to Q 15.ASSERTION REASONING QUESTIONS:- Read the statements carefully and choose the correct alternative from the following: [84]

(a) Both the Assertion and the Reason are correct and the Reason is the correct explanation of the Assertion. (b) The Assertion and the Reason are correct but the Reason is not the correct explanation of the Assertion. (c) Assertion is true but the Reason is false. (d) The statement of the Assertion is false but the Reason is true. Q11. Assertion: Aluminium oxide is an amphoteric oxide. Reason: They react with acid as well as base to form salt and water. Q12. Assertion:Metals are sonorous. Reason: They are generally brittle in solid state and break into pieces when hammered. Q13. Assertion:Sodium and potassium are highly reative metals Reason: Sodium and Potassium are stored under water. Q14. Assertion:Different metals have different reactivities with water and dilute acids. Reason: Reactivity of metal depend on its position in the reactivity series. Q15. Assertion:When Zinc is added to a solution of Ferrous Sulphate,no change is observed. Reason: Zinc is more reactive than Iron. Q16. FILL IN THE BLANKS: - a. Two examples of metals which are poor conductors of heat are ………, ……… . b. Two metals which melt when kept on the palm are ………, ……… . c. A non-metal which is a good conductor of electricity is ……… . d. Metals can form positive ions by ……… . e. A non-metal which is lustrous is ……… . f. A metal which burns in air with a dazzling white flame is ……… . g. Metals above hydrogen in the activity series can displace ……… from dilute acids. h. Metals combines with oxygen to form…………..oxides. SHORT ANSWER QUESTIONS: - Q16. (A) Which of the following metals will melt at body temperature: gallium, magnesium, caesium, aluminium? [85]

(B) Name the two metals which react violently with cold water. Write any three observations you would make when such a metal is dropped into water. How would you identify the gas evolved, if any? (C) What are amphoteric oxides? Choose the amphoteric oxides from- Na2O, ZnO, Al2O3, CO2, H2O (D) From amongst the metals sodium, calcium, aluminium, copper and magnesium, name the metal (I) which reacts with water only on boiling and (II) another which does not react even with steam. LONG ANSWER QUESTIONS: - Q17. (A) Samples of five metals ‘A’, ‘B’, ‘C’, ‘D’ and ‘E’ were taken and added to the following solution one by one. The results obtained have been tabulated as follows. METAL FeSO4 CuSO4 ZnSO4 AgNO3 Al2(SO4) 3 MgSO4 A No Reaction Displacement No Reaction Displacement No No Reaction Reaction B Displacement Displacement No Reaction Displacement No No Reaction Reaction C No Reaction No Reaction No Reaction Displacement No No Reaction Reaction D No Reaction No Reaction No Reaction No Reaction No No Reaction Reaction E Displacement Displacement Displacement Displacement No No Reaction Reaction Use the above table to answer the following questions about the given metals. (a) Which of them is most reactive and why? (b) What would you observe if ‘B’ is added to CuSO4? (c) Arrange ‘A’, ‘B’, ‘C’, ‘D’ and ‘E’ in the increasing order of reactivity. (d) Container of which metal can store zinc sulphate and silver nitrate solution? [86]

(e) Which of the above solution(s) can be stored in a container made of any of these metals and why? (B) A metal ‘X’ loses two electrons and a non-metal ‘Y’ gains one electron. Show the electron dot structure of compound formed between them. Is ionic or covalent? Does it have high melting point or low? Will it conduct electricity in solid state or in aqueous solution and why? Will it be soluble in water? (C) Give reasons for the following: (i) Gold and silver are used for jewellery making. (ii) Aluminium oxide is considered as an amphoteric oxide. (iii) Ionic compounds conduct electricity in molten state. (iv) Metals can be given different shapes according to our needs. (v) Hydrogen is not evolved when a metal reacts with nitric acid. PASSAGE BASED QUESTIONS: - Read the following passage and answer the following questions: - Elements can be classified into the following two groups depending on their physical and chemical properties: • Metals • Non-metals Metals form basic oxides e.g., Magnesium oxide(MgO) , while non-metals form acidic oxides, Carbon dioxide.Different metals show different reactivities towards oxygen present in air. Some metals like Na and K are kept immersed in kerosene oil as they react vigorously with air and catch fire. Some metals like Mg, Al, Zn, Pb react slowly with air and form a protective layer. Mg can also burning air with a white dazzling light to form its oxide Fe and Cu don’t burn in air but combine with oxygen to form oxide.Iron filings burn when sprinkled over flame.Metals like silver, platinum and gold don’t burn or react with air. Usually metal oxides are basic in nature,but some metal oxides show both acidic and basic nature. Amphoteric Oxides :metal oxides which react with both acids as well as bases to form salt and water e.g Aluminium Oxide. (1) Different metals have different reactivities with oxygen: - (a) Oxygen is very reactive (b) Reactivity of metal depend on its position in the reactivity series (c) All metals react with Oxygen [87]

(d) None of the above (2) Example of an amphoteric oxide is: (a) Na2O (b) K2O (C) ZnO (d) MgO (3) An element reacts with oxygen to give a compound with a high melting point. This compound is also soluble in water. The element is likely to be (a) Ca (b) C (c) Si (d) Fe (4) Which of the following oxide(s) of iron would be obtained on prolonged reaction of iron with steam? (a) FeO (b) Fe2O3 (c) Fe3O4 (d) Fe2O3 and Fe3O CHAPTER: CARBON AND ITS COMPOUNDS MUTIPLE CHOICE QUESTIONS: 1 Carbon exists in the atmosphere in the form of (a) Only carbon monoxide (b) Carbon monoxide in traces and carbon dioxide (c) Only carbon dioxide (d) Coal 2 Which of the following statements are usually correct for carbon compounds? These (i) Are good conductors of electricity. (ii) Are poor conductors of electricity. (iii) Have strong forces of attraction between their molecules. (iv) Do not have strong forces of attraction between their molecules. (a) (i) and (iii) (b) (ii) and (iii) (c) (i) and (iv) (d) (ii) and (iv) [88]

3 A molecule of ammonia (NH3) has (a) Only single bonds (b) Only double bonds (c) Only triple bonds (d) Two double bonds and one single bond 4 Buckminsterfullerene is an allotropic form of (a) Phosphorus (b) Sulphur (c) Carbon (d) Tin 5 Which of the following are correct structural isomers of C4H10? (a) (i) and (iii) (b) (ii) and (iv) (c) (i) and (ii) (d) (iii) and (iv) 6.Which of the following is the correct representation of electron dot structure of nitrogen? 7. Structural formula of ethyne is: 8. Identify the unsaturated compounds from the following. (i) Propane (ii) Propene (iii) Propyne (iv) Chloropropane (a) (i) and (ii) (b) (ii) and (iv) (c) (iii) and (iv) (d) (ii) and (iii) 9. Pentane has the molecular formula C5H12. It has [89]

(a) 5 covalent bonds (b) 12 covalent bonds (c) 16 covalent bonds (d) 17 covalent bonds 10. Carbon forms four covalent bonds by sharing its four valence electrons with four univalent atoms, e.g. hydrogen. After the formation of four bonds, carbon attains the electronic configuration of: (a) Helium (b) Neon (c) Argon (d) Krypton 11. The correct electron dot structure of a water molecule is: 12. Which of the following does not belong to the same homologous series? (a) CH4 (b) C2H6 (c) C3H8 (d) C4H8 13. Which of the following is not a straight chain hydrocarbon? 14.Which among the following are unsaturated hydrocarbons? (a) (i) and (iii) (b) (ii) and (iii) (c) (ii) and (iv (d) (iii) and (iv) 15. The heteroatoms present in CH3 ─ CH2 ─ O ─ CH2 ─ CH2Cl are: [90]

(i) Oxygen (ii) Carbon (iii) Hydrogen (iv) Chlorine (a) (i) and (ii) (b) (ii) and (iii) (c) (iii) and (iv) (d) (i) and (iv) 16. The first member of alkyne homologous series is: (a) Ethyne (b) Ethene (C) Propyne (d) Methane ASSERTION REASON: In the following questions Assertion and reasons have been put forward. Read the statements carefully and choose the correct alternative from the following: (a) Both the Assertion and Reason are correct and the Reason is the correct explanation of the Assertion. (b) Both the Assertion and Reason are correct but the Reason is not the correct explanation of the Assertion. (c) Assertion is true but reason is false. (d) The statement of the Assertion is false but the Reason is true. 1.Assertion: Methane is the simplest saturated hydrocarbon which is the major component of natural gas. Reason: Methane belongs to alkene. 2.Assertion: Unsaturated hydrocarbons include alkene and alkyne families. Reason: Alkene and alkyne family are formed by a single covalent bond between two Carbon atoms. 3.Assertion: n- butane and iso-butane are isomers. Reason: Isomers are compounds which have the same molecular formula and different structural formula. 4.Assertion: Diamond is the hardest known substance. Reason: Each Carbon atom is linked to three carbon atoms. 5. Assertion: Carbon forms a large number of compounds. [91]

Reason: Carbon shows tetravalency and a property of self-linkage. 6. Assertion: Covalent compounds are bad conductors of electricity. Reason: Covalent compounds do not dissociate in ions when dissolved in water. 7. Assertion: In the compound CCl4carbon loses four electrons to form bonds with chlorine Reason: Carbon has the ability to lose electron due to its small size 8. Assertion: Carbon has the unique property to form long chain compounds. Reason: This property is called tetra covalency. 9. Assertion: Diamond and Fullerene are allotropes of carbon. Reason: They have different chemical formulas but the same physical properties. 10. Assertion: Water is an ionic compound and conducts electricity. Reason: Water molecules are formed by sharing of electrons between Oxygen and hydrogen Atoms. PARAGRAPH BASED QUESTIONS I) Read the given passage and answer the questions based on passage and related studied concepts. Carbon has four valence electrons. It cannot lose or gain four electrons. It can share four electrons easily. It forms a large number of covalent compounds due to the property of catenation and tetravalency. Carbon has three crystalline allotropes-diamond, graphite and fullerene which differ in physical properties. Alkanes are saturated hydrocarbons, undergo combustion and substitution reactions. Alkenes and alkynes are unsaturated hydrocarbons and undergo addition reactions. (a) Why are covalent compounds poor conductors of electricity? (b) A compound 'X' on combustion gives a yellow flame with lots of smoke. What inference would you draw from this statement? (c) State any four differences between ionic and covalent compounds. (d) Why is Carbon able to form a large number of compounds? (e) Name the allotropes of Carbon. VSA/SHORT ANSWERS 1.Why does carbon form a large number of compounds? 2.Why covalent compounds have low melting and boiling points? 3.Diamond and graphite show different physical properties although they are made up of carbon and show the same chemical properties. What is the property called? 4.Why Carbon does not form an ionic compound? [92]

5. Mention any four differences between ionic and covalent compou6.Name the black substance of pencil. Will the current flow through the electrical circuit when we use the sharpened pencils to complete the circuit? 7.What are hydrocarbons? Give examples. 8. Why are homologous series of compounds so called? Write chemical formula of two consecutive members of a homologous series and state the part of these compounds that determines their (i) physical properties (ii) chemical properties. 8.Elements forming ionic compounds attain noble gas configuration by eitheir gaining or by loosing electron from their valence shells. Explain giving reasons why carbon cannot attain such a configuration in this manner to form compounds. Name the type of the bond formed by ionic compounds and in the compounds formed by Carbon. Also explain with reason why carbon compounds are generally 9.(a) Write molecular formula of the third and fifth member of homologous series of compounds represented by general formula CnH2n+2 (b) Write lower homologue and higher homologue ofC2H6 10.Draw the electron dot structures of the following compounds a. CH4 b. H2O c. NH3 11. Define homologous series and mention any four characteristics. 12.Write the general formula of alkane, alkene and alkyne. 13.Draw the electron dot structure of ethyne and also draw its structural formula LONG ANSWERS 1.Carbon, Group (14) element in the Periodic Table, is known to form compounds with many elements. Write an example of a compound formed with ● (a) chlorine (Group 17 of Periodic Table) ● (b) oxygen (Group 16 of Periodic Table) 2.In electron dot structure, the valence shell electrons are represented by crosses or dots. (a) The atomic number of chlorine is 17. Write its electronic configuration (b) Draw the electron dot structure of chlorine molecule. 3.(a) . Explain the term isomers. Give one example of isomers. (b) Write the (i) structural formula and (ii) electron dot isomer of butane. (c) Write the IUPAC name of the compound having formula n-C4H10 [93]

CHAPTER: PERIODIC CLASSIFICATION OF ELEMENTS MULTIPLE CHOICE QUESTIONS 1. Which of the following factors does not affect the metallic character of an element? i). Atomic size ii). Ionisation potential iii). Electronegativity iv). Atomic radius 2. The family of elements to which potassium belongs is _________. i). alkali metals ii). alkaline earth metals iii). halogens iv). noble gases 3. The modern periodic table is given by ________ i). Mendeleev ii). Einstein iii). Bohr iv). Mosley 4. Elements belonging to groups 1 to 17 are called __________. i). noble gases ii). normal elements iii). transition elements iv). inner transition elements 5. A liquid non-metal is ___________. i). phosphorous ii). mercury iii). bromine iv). Nitrogen 6. The first alkali metal is _________. i). hydrogen [94]

ii). lithium iii). sodium iv). Francium 7. A purple coloured solid halogen is ________. i). chlorine ii). bromine iii). iodine iv). Astatine 8. Lanthanides and actinides are also called ___________. i). normal elements ii). transition elements iii). noble gases iv). inner transition elements 9. The family of elements to which calcium belongs is __________. i). alkali metals ii). alkaline earth metals iii). halogens iv). noble gases 10. The least reactive element in group 17 is ___________. i). fluorine ii). chlorine iii). bromine iv). Iodine 11. The valency of chlorine with respect to oxygen is __________. i). 1 ii). 3 iii). 5 iv). 7 12. The number of shells in the elements of 3rd period is __________. [95]

i). 1 ii). 2 iii). 3 iv). 0 13. Four elements along a period have atomic number (11, 13, 16 and 17). The most metallic among these has an atomic number of __________. i). 11 ii). 12 iii). 16 iv). 17 14. Six elements A, B, C, D, E and F have the following atomic numbers (A = 12, B = 17, C = 18, D= 7, E = 9 and F = 11) . Among these elements, the element, which belongs to the 3rd period and has the highest ionisation potential, is __________. i). A ii). B iii). C iv). F 15. A factor that affects the ionisation potential of an element is __________. i). atomic size ii). electron affinity iii). electro-negativity iv). Neutrons 16. In Mendeleev ’s Periodic Table, gaps were left for the elements to be discovered later. Which of the following elements found a place in the perioidc table later i). Germanium ii). Chlorine iii). Oxygen iv). Silicon 17. Which of the following statement (s) about the Modern Periodic Table are incorrect (i) The elements in the Modern Periodic Table are arranged on the basis of their decreasing atomic number [96]

(ii) The elements in the Modern Periodic Table are arranged on the basis of their increasing atomic masses (iii) Isotopes are placed in adjoining group (s) in the Periodic Table (iv) The elements in the Modern Periodic Table are arranged on the basis of their increasing atomic number (a) (i) only (b) (i) , (ii) and (iii) (c) (i) , (ii) and (iv) (d) (iv) only 18. Which of the following statements about the Modern Periodic Table is correct: i). It has 18 horizontal rows known as Periods ii). It has 7 vertical columns known as Periods iii). It has 18 vertical columns known as Groups iv). It has 7 horizontal rows known as Groups 19. Which of the given elements A, B, C, D and E with atomic number 2, 3, 7, 10 and 30 respectively belong to the same period? i). A, B, C ii). B, C, D iii). A, D, E iv). B, D, E 20. The elements A, B, C, D and E have atomic number 9, 11, 17, 12 and 13 respectively. Which pair of elements belong to the same group? i) A and B ii) B and D iii) A and C iv). D and E 21. Where would you locate the element with electronic configuration 2,8 in the Modern Periodic Table? i). Group 8 ii). Group 2 iii). Group 18 iv). Group 10 [97]

22. An element which is an essential constituent of all organic compounds belongs to i). group 1 ii). group 14 iii). group 15 iv). group 16 23. Which of the following is the outermost shell for elements of period 2? i). K shell ii). L shell iii). M shell iv). N shell 24. Which one of the following elements exhibit maximum number of valence electrons? i) Na ii) Al iii) Si iv) P 25. Which of the following gives the correct increasing order of the atomic radii of O, F and N? i) O, F, N ii) N, F, O iii) O, N, F iv) F, O, N 26. Which among the following elements has the largest atomic radii? i). Na ii). Mg iii). K iv). Ca 27. Which of the following elements would lose an electron easily? i). Mg ii). Na iii). K iv). Ca ASSERTION AND REASONING TYPE QUESTIONS Directions (Q. Nos. 1 – 10) In the following questions a statement of Assertion is followed by a statement of Reason. Mark the correct choice as: (a) If both Assertion and Reason are true and Reason is the correct explanation of Assertion. [98]

(b) If both Assertion and Reason are true but Reason is not the correct explanation of Assertion. · (c) If Assertion is true but Reason is false. (d) If Reason is true but Assertion is false. (e) If both Assertion and Reason are false. Q1. Assertion: Atomic size of potassium is greater than that of sodium. Reason: As we go down the group, atomic radius increases. Q2. Assertion: Alkali metals have smallest size in a period. Reason: They are at the extreme left of the periodic table. Q3. Assertion: All first group elements are metals Reason: The number of valence electron is 1 Q4. Assertion: In the long form of periodic table, different isotopes can be placed at the same place because they have same atomic mass. Reason: Atomic mass is the mass of an electron and proton. Q5. Assertion: The group 18 is also known as zero group Reason: The no of valence electron is zero. Q6. Assertion: A horizontal row of a periodic table is called a period. Reason: A vertical column of elements in the periodic table is called a group. Q7. Assertion: Newlands suggested that when the elements are arranged in the order of increasing atomic masses,the properties of every eight element are a repetition of that of the first element. Reason: Newland called this relation as a law of octaves due to the similarity with the musical scale. Q8. Assertion: Mendeleev predicated the properties of those missing elements from the known properties of the other elements in the same group Reason: Copper (Cu), silver (Ag) and gold (Au) were missing elements Q9. Assertion: Elements of group 1 and 2 are called alkali metals and alkaline earth metals respectively. Reason: Alkalis are water insoluble bases. Q10. Assertion: Elements present in group 17 are called halogens Reason: All halogens are gases. [99]

VERY SHORT ANSWER QUESTIONS(1 mark each) Q1. What is meant by classification of elements? Q2. What was the limitation of Dobereiner law of triads? Q3. Why do Li, Na and K how resemblance on the basis of Dobereiner’s law of triads? Q4. Classify the following elements according to the Law of Octaves: K, Na, Ca, S, O, P, Al N, F, Si, C, Cl, Mg Q5. A, B and C are elements of Dobereiner’s triad. If the atomic mass of A is 7 and that of C s 23, what will be the atomic mass of B. Q6. Classify the following elements into groups of triads Cl, Ca, Ba, Sr, K, Li, Br, I, Na Q7. Na and K resemble in their properties, how many elements are there between them? Q8. State Mendeleev’s law. Q9. Mendeleev classified the elements on the basis of two factors. What were these two factors? Q10. What is meant by ‘groups’ of Periodic Table? Q11. What is meant by periodicity of properties? Q12. Name two elements whose valencies are equal to their group number. Q13. What are the elements of group 1 and group 17? Q14. Which one has the bigger size? Na (11) or Cl (17) , Cl (17) or F (9) Q15. What would be the nature of oxides formed by the element on the left hand side of the periodic table? Give one example. Q16. How many shells are present in the elements of 3rd period? Give reason also. Q17. An element ‘X’ has atomic number 20. To which group and period does it belong? Q18. Find the atomic number of the element whose electronic configuration is 2, 8, 5. Q19. Arrange the following elements increasing order of their atomic radii: Li, Be, F, N Cl, At, Br, I Q20. Out of Li and K, which will have stronger metallic character and why? Q21. Write the number of horizontal rows in the modern periodic table. What are these rows called? Q22. Give the number of elements in 2nd and 5th period in Modern Periodic Table. [100]