O-LevelChemistryOrganic Chemistry5070/22 · May/June 2019 · Q1010 Marks

The structures of cyclobutanol and butanoic acid are shown. [Figure 10.1]

(a)Explain why cyclobutanol is not a hydrocarbon.[1]
(b)Explain why butanoic acid is a saturated compound.[1]
(c)Describe a chemical test that can distinguish cyclobutanol from butanoic acid. test ............................................................................................................................................ result for cyclobutanol ............................................................................................................... result for butanoic acid .............................................................................................................[3]
(d)Calculate the percentage by mass of carbon in cyclobutanol. percentage by mass ............................................................[2]
(e)(i)Ethanol can be converted into methyl ethanoate in a two-step process. [Figure 10.2] (i) Identify compound X.[1]
(e)(ii)Identify the reagent used in step 1.[1]
(e)(iii)Identify the reagent used in step 2.[1]

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Mark scheme

Marking points from the official mark scheme (May/June 2019). The mark or mark type is shown in brackets.

[1] 10(a) contains oxygen (atom)
[1] 10(b) does not have any carbon-carbon double bonds / all the carbon-carbon bonds are single bonds / the carbon-carbon bonds are only single bonds
[3] 10(c) EITHER test: Universal indicator (1) cyclobutanol: goes green / does not change colour (1) butanoic acid: goes red / orange or yellow (1) OR test: heat with named alcohol (1) cyclobutanol: no reaction (1) butanoic acid: gives sweet smelling compound (1) OR test: heat with named carboxylic acid (1) cyclobutanol: gives sweet smelling compound (1) butanoic acid: no reaction (1)
[2] 10(d) M₁ = 72 (1) % = 66.7 / 67 (1)
[1] 10(e)(i) ethanoic acid / CH3COOH
[1] 10(e)(ii) (acidified) potassium manganate(VII)
[1] 10(e)(iii) methanol

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