2020Science(Chemistry)(1)

1/5 Achievement test (Chemistry) No.) Name) 1. The chart below explains properties of five gases. (1) Choose the gas from below (A)~(E) that matches each of the explanations. Write answers in ( ) below table with the symbols (A)~(E). (A) Hydrogen, (B) Nitrogen, (C) Oxygen, (D) Ammonia, (E) Carbon dioxide No. 1 No. 2 No. 3 No. 4 No. 5 Colorless Colorless Colorless Colorless Colorless Odorless Odorless Odorless Odorless Characteristic pungent odor It has the property of It makes lime It occupies 4/5 of It forms water Its water solution burning a substance water milky volume of air when reacted shows alkaline with oxygen Related question (2) Related question (3) Name of gas ( )( )( ) ( ) () (2) As for the gas (No. 1), choose the appropriate method for generating the gas from below. Write answer with a symbol (a), (b) or (c). (a) Put a piece of zinc into the dilute hydrochloric acid solution. (b) Heat a silver oxide. (c) Put a lime stone into the dilute hydrochloric acid solution. Answer) (3) As for the gas (No. 5), choose the appropriate method for collecting the gas from below. Write answer with a symbol (a), (b) or (c). (a) Upward delivery (b) Downward delivery (c) Collect over water Answer)

2/5 Achievement test (Chemistry) No.) Name) 2. A solid substance is placed in a test tube and heated slowly. The graph on the below shows the temperature change of the substance. Temperature Heating time (1) What state the substance is in at the point A~E ? Choose the appropriate state from below (a)~(e) and answer with symbols in the chart below. (a) Gas, (b) Liquid, (c) Solid, (d) Coexistence of liquid and gas, (e) Coexistence of solid and liquid Point on the graph A B C D E State of substance (2) When the temperature at the point B is 0 ℃ and point D is 100 ℃, what substance is used in this experiment? Answer with a chemical equation. Answer) 3. The electrolysis of water produces two gases. (1) What is the gas produced at the negative electrode (-) ? Answer with a chemical equation. Answer) (2) What is the gas produced at the positive electrode (+) ? Answer with a chemical equation. Answer) (3) Express the electrolysis of water with a chemical reaction equation. Answer) (4) Find the volume ratios of the gases produced at the negative and positive electrode. Negative electrode (-) : Positive electrode (+) = :

3/5 Achievement test (Chemistry) No.) Name) 4. Fill in the chart below with the element symbols (atomic symbol). Name Hydrogen Carbon Nitrogen Oxygen Sulphur Natrium Element symbol Name Aluminum Calcium Iron Copper Element symbol 5. Express the following substances with chemical equations. (1) Oxygen molecule …( ) (2) Water……( ) ) (3) Carbon dioxide ……( ) (4) Ammonia……( (5) Natrium chloride……( ) 6. Express the following chemical changes with chemical reaction equations. (1) Carbon combines with oxygen to form carbon dioxide. Answer) (2) Silver oxide decomposes into silver and oxygen by heating. Answer) (3) Sodium hydrogen carbonate decomposes into sodium carbonate, carbon dioxide and water by heating. Answer) (4) Copper combines with oxygen to form copper oxide. Answer) (5) Iron combines with Sulphur to form iron sulfide. Answer) 7. Classify the following substances (a)~(e) into simple substances and chemical compounds. Write answers with the symbols (a)~(e). (a) Hydrogen gas, (b) Water, (c) Iron, (d) Carbon dioxide, (e) Ammonia gas Simple substance Chemical compound

4/5 Achievement test (Chemistry) No.) Name) 8. Classify the following symbols (a)~(g) into organic and inorganic substances. Write answers with symbols (a)~(g). (a) Sugar, (b) Glass, (c) Salt, (d) Flour, (e) Copper, (f) Plastic, (g) Paper Organic Inorganic 9. Solutions of A～E are any of the following solutions. (a) Dilute hydrochloric acid (b) Dilute nitric acid (c) Dilute sodium hydroxide solution (d) Dilute calcium hydroxide solution (e) Salt solution (＊) Pour small amounts of solutions A~E into each test tube, and add the green BTB solution into them. • Solutions A and D change to yellow. • Solutions C and E change to blue. • Solution B remains green. (＊) When carbon dioxide is added into solution C, a white precipitate is formed. (＊) When solution E is added slowly into solution D, it changes from yellow to green. White substances appear as a result of the vaporization of the solution. This is the same substances when solution B is vaporized. Find solutions of A～E. Choose one from above and write answers with symbols (a)~(e). (Answers) ABCD E 10. The following chart shows the relationship between temperature and the maximum mass of potassium nitrate that can dissolve in a 100 g of water (solubility). Temperature (℃) 20 40 60 80 Maximum mass (g) 31.6 63.9 109.2 168.8 (1) How many grams (g) of potassium nitrate can dissolve in a 80 g of water at 40 ℃ ? Answer) (2) A saturated solution of potassium nitrate is formed at 60 ℃. Calculate the mass percent concentration of the solution. Answer) (3) Potassium nitrate is dissolved in a 100 g of water at 80 ℃ until it becomes a saturated solution (the maximum amount of a substance that can be dissolved). When this saturated solution is cooled down to 40 ℃, how many grams (g) of potassium nitrate will come out of the solution as crystals? Answer)

5/5 Achievement test (Chemistry) No.) Name) 11. 2.00 g of sodium hydrogen carbonate are added each time into the beaker containing a certain amount of concentration and volume of hydrochloric acid. Measure the mass of carbon dioxide produced by each reaction. The results are shown in the following chart. Number of experiments 12345 Mass of sodium hydrogen 2.00 2.00 2.00 2.00 2.00 carbonate (g) Mass of carbon dioxide 0.52 0.52 0.13 0.00 produced (g) (1) In the chart above, the mass of carbon dioxide produced in the second experiment is not written. How many grams (g) of carbon dioxide are produced? Answer) (2) In the fourth experiment, how many grams (g) of sodium hydrogen carbonate are used to produce 0.26 g of carbon dioxide? Answer) (3) In the fourth experiment, some of the sodium hydrogen carbonate remain unused in the reaction. We want all the remaining sodium hydrogen carbonate reacted to produce carbon dioxide. Choose an appropriate operation from the following. (a) Add sodium hydroxide solution (b) Add water (c) Add hydrochloric acid Answer)