Organic chemistry Banker

1. (a) Which compound is an alkane?A C₅H₁₀B C₅H₁₂C C₅H₈D C₅H₁₁OH [1]

1. (a) State three characteristics of a homologous series. [3]
2. (b) Give the name of the homologous series with the functional group –OH. [1]

1. (a) Explain what is meant by structural isomers. [2]
2. (b) Give the structural formulae of the two structural isomers with molecular formula C₄H₁₀. [2]
3. (c) Name the unbranched isomer. [1]

1. (a) Name the functional group present in each compound: (i) propanoic acid, (ii) but-1-ene, (iii) propan-1-ol. [3]
2. (b) But-1-ene and but-2-ene have the formula C₄H₈. Give the structural formula of each and state how they are related. [3]

1. (a) Name the compounds: (i) CH₃CH₂OH, (ii) CH₃COOH, (iii) CH₃CH=CH₂, (iv) CH₃COOCH₃. [4]
2. (b) Give the molecular formula of the alkene with six carbon atoms and calculate its relative molecular mass. [Ar: C = 12, H = 1] [2]

1. (a) Name the type of polymerisation used to make poly(ethene) from ethene. [1]
2. (b) Give the repeat unit of poly(ethene) as a structural formula. [1]
3. (c) Give two problems caused by the disposal of poly(ethene) shopping bags. [2]

1. (a) Suggest why plastic bottles found on a beach in Karachi can stay there for hundreds of years. [1]
2. (b) Give one disadvantage of burning waste plastics. [1]
3. (c) Suggest one way of reducing the amount of plastic waste. [1]

1. (a) Poly(chloroethene) is used to make water pipes. What is its monomer?A CH₃CH₂ClB CH₂=CHClC CH₂Cl–CH₂ClD CCl₂=CCl₂ [1]

Poly(propene) is used to make ropes for fishing boats in Gwadar. It is made from propene, CH₃CH=CH₂.

1. (a) Give the structural formula of the repeat unit of poly(propene). [1]
2. (b) Calculate the relative formula mass of one repeat unit. [Ar: C = 12, H = 1] [1]
3. (c) A molecule of poly(propene) has a relative molecular mass of 84 000. Calculate the number of repeat units in the molecule. [1]

Lentils (daal) are a good source of protein.

1. (a) Name the monomers from which proteins are made. [1]
2. (b) Proteins are natural polyamides. Name the type of polymerisation that forms them. [1]
3. (c) Give the name of the small molecule released each time two monomers join. [1]
4. (d) State the name of the synthetic polymer that has the same linkage as proteins. [1]

1. (a) Nylon is made from a dicarboxylic acid and a diamine. Name the type of polymerisation and the small molecule formed. [2]
2. (b) Name the linkage in nylon and give its structure. [2]
3. (c) PET is made from a dicarboxylic acid and a diol. Name the type of linkage in PET. [1]
4. (d) State two differences between addition polymerisation and condensation polymerisation. [2]

1. (a) PET is used to make drinks bottles. Which linkage joins the monomer units in PET?A –CONH–B –COO–C –C=C–D –O–H [1]

1. (a) Name the process used to separate petroleum into fractions. [1]
2. (b) Give one use of each fraction: (i) refinery gas, (ii) kerosene, (iii) bitumen, (iv) naphtha. [4]
3. (c) Describe how chain length changes from the top to the bottom of the fractionating column. [1]

1. (a) State two conditions used to crack long-chain alkanes. [2]
2. (b) Complete the equation: C₁₀H₂₂ → C₈H₁₈ + ______ [1]
3. (c) Give two reasons why cracking is carried out. [2]

1. (a) Hexadecane, C₁₆H₃₄, is cracked to form octane, C₈H₁₈, two molecules of propene and one molecule of compound Z. Deduce the molecular formula of Z. [2]
2. (b) Name compound Z and state the homologous series to which it belongs. [2]
3. (c) Explain why the supply of long-chain fractions from fractional distillation is greater than the demand for them. [1]

1. (a) What are the products of the complete combustion of ethanol?A carbon monoxide and waterB carbon dioxide and hydrogenC carbon dioxide and waterD carbon and water [1]

1. (a) Give two uses of ethanol. [2]
2. (b) Write the balanced equation for the complete combustion of ethanol. [2]

Pakistan makes ethanol from sugar-cane molasses. Ethanol can also be made from ethene.

1. (a) Give the conditions for making ethanol by fermentation. [3]
2. (b) Give the conditions for making ethanol from ethene and steam. [3]
3. (c) Give one advantage of fermentation and one advantage of the hydration of ethene. [2]

C₆H₁₂O₆ → 2C₂H₅OH + 2CO₂

1. (a) Calculate the maximum mass of ethanol formed from 45 g of glucose. [Mr: glucose = 180, ethanol = 46] [3]
2. (b) Calculate the volume of carbon dioxide formed at room temperature and pressure, in dm³. [1 mol of gas occupies 24 dm³ at r.t.p.] [2]
3. (c) Suggest why the fermentation stops when the ethanol concentration reaches about 15 %. [1]

Vinegar contains ethanoic acid.

1. (a) Describe what is seen when magnesium ribbon is added to aqueous ethanoic acid, and name the products. [3]
2. (b) Name the salt formed when ethanoic acid reacts with sodium carbonate. [1]
3. (c) Ethanoic acid is a weak acid. Explain what this means. [1]

1. (a) Which ester is formed when ethanol reacts with propanoic acid?A propyl ethanoateB ethyl propanoateC ethyl ethanoateD propyl propanoate [1]

1. (a) State the conditions needed to make an ester from an alcohol and a carboxylic acid. [2]
2. (b) Write the word equation for the reaction between methanol and ethanoic acid. [2]
3. (c) Give one use of esters. [1]

1. (a) Ethanoic acid can be made by heating ethanol with acidified potassium manganate(VII). State the colour change and the type of reaction. [2]
2. (b) Name another method of making ethanoic acid from ethanol. [1]
3. (c) Calculate the maximum mass of ethanoic acid that can be made from 9.2 g of ethanol. [Mr: ethanol = 46, ethanoic acid = 60] [2]

1. (a) Propyl ethanoate smells of pears. Name the alcohol and the carboxylic acid used to make it. [2]
2. (b) Give the structural formula of propyl ethanoate. [1]
3. (c) Give the molecular formula of propyl ethanoate and calculate its relative molecular mass. [Ar: C = 12, H = 1, O = 16] [2]

Two unlabelled bottles contain hexane and hexene.

1. (a) Describe a chemical test to show which liquid is hexene. [2]
2. (b) Explain why hexene is described as unsaturated. [1]

1. (a) Name the product when ethene reacts with hydrogen, and state the catalyst. [2]
2. (b) Name the product when ethene reacts with steam. [1]
3. (c) Name the product when ethene reacts with bromine. [1]
4. (d) State the type of reaction in (a), (b) and (c). [1]

1. (a) Propene reacts with bromine. What is the molecular formula of the product?A C₃H₅BrB C₃H₆Br₂C C₃H₇BrD C₃H₈Br₂ [1]

LPG cylinders used for cooking in many Pakistani homes contain propane.

1. (a) Write the balanced equation for the complete combustion of propane. [2]
2. (b) Name the toxic gas produced if the supply of air to the cooker is limited. [1]
3. (c) Apart from combustion, alkanes are generally unreactive. Explain why, in terms of bonding. [1]

1. (a) Name the type of reaction between methane and chlorine. [1]
2. (b) State the condition needed. [1]
3. (c) Write the equation for the reaction that forms chloromethane. [2]
4. (d) Explain the role of the UV light. [1]

1. (a) 50 cm³ of butane, C₄H₁₀, is burned completely in oxygen. All volumes are measured at the same temperature and pressure. What volume of oxygen is needed?A 200 cm³B 250 cm³C 325 cm³D 400 cm³ [1]