IGCSE CHEMISTRY EDEXCEL (9-1) -Mr. EHAB FAROUK 0097455339573

Isomerism Structural Isomerism in Alkanes Isomers of C4H10 Straight chain (unbranched alkane)

Isomerism Isomers of C5H12

Isomerism Structural Isomerism in Alkenes Isomers of C4H8 You can change the position of the double bond as well as branching the chain.

ALKANES (CnH2n+2) Alkanes: are hydrocarbon compounds that contain carbon and hydrogen only with single covalent bonds between carbon atoms C-C Alkanes forms Homologous series because: - The have the same general formula - They have similar structural formula - They have similar chemical properties

ALKANES (CnH2n+2) The graduation in the boiling points of Alkanes

ALKANES (CnH2n+2) Explain: the boiling point in alkanes increase in a regular way Because as the molecules become bigger, the strength of the intermolecular attraction forces increase. So, more energy is needed to break the attraction between molecules. So, the boiling point increase gradually

Reactions of Alkanes 1- Combustion reaction: a- Complete combustion: there is enough oxygen, they burn completely to give carbon dioxide and water vapour

Reactions of Alkanes 1- Combustion reaction: b- Incomplete combustion: there is not enough oxygen, there is incomplete combustion of alkane and obtain carbon monoxide or carbon (soot) and water vapour

Reactions of Alkanes 2- Substitution reaction: one atom has been replaced by a different one Alkanes react with halogens in the presence of ultraviolet radiation Bromine gas Mixture of bromomethane (orange colour) and hydrogen bromide (colourless)

Reactions of Alkanes Reaction of ethane with chlorine exposed to UV light Structural isomerism

ALKENES (CnH2n) Alkenes: are unsaturated compounds because they contain a C=C bond

Reaction of Alkenes 1- combustion reaction: Alkenes burn in air or oxygen to give carbon dioxide and water vapour Explain: Alkenes are more active than Alkanes. Because in alkenes part of the double bond breaks to become a single C-C bond and electrons are used to join other atoms.

Reaction of Alkenes 2- Addition reaction: Alkenes undergo addition reaction a- Addition of Bromine (Br2)

Test for C=C bond (alkenes)

Test for C=C bond (alkenes) Test Observation Conclusion Shake the unknown organic Orange bromine water is Compound has C=C bond compound (alkene) with Bromine water (orange) decolorized (from orange to colourless)

Reaction of Alkenes 3- Hydration reaction: It is reaction involves the addition of water (Alkenes reacts with water to form an alcohol) Ethene steam Ethanol

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CHEMISTRY (9-1) Alcohols Carboxylic acids - Esters PREPARED BY: Mr. EHAB FAROUK 55339573

Alcohols (-OH)

Alcohols (-OH) Explain: Alcohols are considered as Homologous series Because they have: 1- the same general formula 2- similar in the chemical properties because they have the same function group (-OH)

Alcohols (-OH) OXIDATION OF ETHANOL 1-Ethanol burns in Air All alcohols burn to form carbon dioxide and water vapour Ethanol as BIOFUEL A fuel that is made from biological sources a sugar cane and corn Biofuels are renewable resource – Fossil fuels are non-renewable resources

Alcohols (-OH) OXIDATION OF ETHANOL 2-Ethanol oxidized by air in the presence of MICROBES (Microbial Oxidation) Ethanol in the wine is oxidized by air with the help of microorganisms as Bacteria or Yeast to form Ethanoic acid (acetic acid) CH3COOH. (O) oxidation

Alcohols (-OH) OXIDATION OF ETHANOL 3- Oxidation of Ethanol by Potassium Dichromate (VI) in dilute Sulphuric acid. Potassium dichromate (VI)- K2Cr2O7 is strong oxidizing agent Test Observation Conclusion A few drops of ethanol are The solution turns Ethanol can be oxidized added to a solution containing green that indicates the by potassium Orange mixture of potassium presence of dichromate and dilute dichromate and dilute sulphuric sulphuric acid into acid in a test tube that heated in ETHANOIC ACID a hot water bath

Alcohols (-OH) 3- Oxidation of Ethanol by Potassium Dichromate (VI) in dilute Sulphuric acid.

Production Of Ethanol (CH3CH2OH) 1- Fermentation process Absence of air Temperature (anaerobic 30 – 40oC conditions) Yeast The enzymes in yeast acts (ENZYMES) As CATALYST Sugar (starch) solution Ethanol + Carbon dioxide

Production Of Ethanol (CH3CH2OH) 1- Fermentation process What is happened: if the temperature is increased much above 40oC The Enzyme (protein) lose their structure and do not work (Denatured)

Production Of Ethanol (CH3CH2OH) 2- Hydration of Ethene (Hydration means reacting with steam) Only a small amount of the Ethene reacts. the Ethanol produced is condensed as a liquid and unreacted ethene is recycled.

Comparing the two methods of producing Ethanol

Carboxylic Acids (-COOH)

Carboxylic Acids (-COOH) Carboxylic acids react like the other acids: 1- The reaction with Metals Metals react with aqueous carboxylic acid (vinegar) to give salts and hydrogen gas. This reaction is slow because carboxylic acids are weak acids

Carboxylic Acids (-COOH) Carboxylic acids react like the other acids: 2- The reaction with Carbonates carbonates react with aqueous carboxylic acid (vinegar) to give salts , carbon dioxide and water.

Esters (-COOR) Alcohol + carboxylic acid → ester + water Using sulphuric acid as catalyst Ethanol + ethanoic acid → ethyl ethanoate + water methanol + propanoic acid → methyl propanoate + water

Esters (-COOR)

Esters (-COOR) Esters + w������������������������ → alcohol + carboxylic acid

Esters (-COOR) Ester Formation (practical)

Esters (-COOR) Uses of Esters 1- small esters are used as solvent 2- used in food flavourings and perfumes

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CHEMISTRY (9-1) Polymerisation PREPARED BY: Mr. EHAB FAROUK 55339573

Polymerisation Polymerisation It is the joining up of lots of little molecules (monomers) to make one big molecule (polymer) Addition Polymerisation Molecules simply added onto each other without anything else being formed.

1- Addition Polymerisation Polymerisation of Ethene CH2=CH2 Initiator is used to start the process and not catalyst because it is consumed in the process Polymer

1- Addition Polymerisation Polymerisation of Ethene CH2=CH2 Ethene Poly(ethene) (monomer)

1- Addition Polymerisation Polymerisation of Ethene CH2=CH2

1- Addition Polymerisation Polymerisation of Ethene CH2=CH2 Monomer Polymer Repeat unit

1- Addition Polymerisation uses of poly(ethene) uses HDPE LDPE properties high density poly(ethene) Low density poly(ethene) Make plastic bottles Used for poly(ethene) bags as milk bottles It is very flexible and It has greater strength not very strong and more rigid

1- Addition Polymerisation Formation of poly(propene)

1- Addition Polymerisation Formation of poly(propene) propene Poly(propene) Uses of poly(propene) It is more stronger than poly(ethene) so, used to make ropes and crates

1- Addition Polymerisation Formation of poly(chloroethene) (polyvinylchloride)-PVC

1- Addition Polymerisation Formation of poly(chloroethene) (polyvinylchloride)-PVC chloroethene Poly(chloroethene)

Uses of poly(chloroethene) Property Use of poly(chloroethene)-PVC Strong and rigid Used in for water pipes or replacement windows Used in floor coverings and clothing Flexible by adding plasticisers Don’t conduct electricity PVC can be used for electrical insulators

1- Addition Polymerisation Formation of poly (tetrafluoroethene)