A chemist has four unlabelled colourless liquids, W, X, Y and Z.
Each liquid is made of straight-chain molecules.
The chemist finds the molecular formula of each liquid and tests each liquid with bromine water and with sodium carbonate solution.
The table shows the results.
| Liquid | Molecular formula | Bromine water | Sodium carbonate solution |
|---|---|---|---|
| W | C5H12\mathrm{C_{5}H_{12}}C5H12 | stays orange | no change |
| X | C5H10\mathrm{C_{5}H_{10}}C5H10 | orange to colourless | no change |
| Y | C4H8O2\mathrm{C_{4}H_{8}O_{2}}C4H8O2 | stays orange | fizzes |
| Z | C4H10O\mathrm{C_{4}H_{10}O}C4H10O | stays orange | no change |
Identify the homologous series of each liquid.
Use the formulae and the results in the table.
Liquid Z is oxidised to make liquid Y.
Name liquid Y and liquid Z.
Liquid X reacts with hydrogen, with bromine and with steam.
Predict the molecular formula of the product of each reaction.
| Substance reacting with X | Molecular formula of product |
|---|---|
| hydrogen | ? |
| bromine | ? |
| steam | ? |
Write your answers in the table.
Alkene Q has a relative formula mass of 84.0.
Deduce the molecular formula of Q.
Relative atomic masses (Ar): C = 12.0 H = 1.0
Alkene Q reacts with bromine in the same way as ethene, even though Q is a much larger molecule.
Explain why.
63 exam-style questions on OCR GCSE Chemistry 6.2 Organic chemistry, covering 6.2.1 Crude oil and fractional distillation, 6.2.2 Cracking and dependence on hydrocarbons, 6.2.3 Functional groups and homologous series, 6.2.4 Reactions of alkanes, alkenes and alcohols, 6.2.5 Addition polymerisation and repeat units, 6.2.6 Naturally occurring polymers, 6.2.7 Chemical cells and fuel cells, and 6.2.8 Condensation polymerisation and how to make one. Each one has a worked solution and a mark scheme showing where the marks go.