Chemistry 5070 · O Level · Alkenes

Alkenes — practice question

The displayed structure of fumaric acid is shown.
(a)[1]

In what way does this structure indicate that fumaric acid is an unsaturated compound?

(b)[2]

Fumaric acid is oxidised by acidified aqueous potassium manganate(VII). What colour change would you see in the reaction mixture when excess aqueous fumaric acid is added to acidified aqueous potassium manganate(VII)? from ................. to .................

(c(i))[1]

Aqueous sodium hydroxide neutralises fumaric acid. $\text{C}_2\text{H}_2(\text{COOH})_2 + 2\text{NaOH} \rightarrow \text{C}_2\text{H}_2(\text{COONa})_2 + 2\text{H}_2\text{O}$. Write the ionic equation for this reaction.

(c(ii))[3]

Calculate the volume of $0.0500\,\text{mol dm}^{-3}$ sodium hydroxide needed to neutralise $20.0\,\text{cm}^3$ of $0.0200\,\text{mol dm}^{-3}$ fumaric acid. Give your answer to three significant figures.

Worked solution & mark scheme

This 7-mark question has a full step-by-step worked solution and mark scheme. One marking point: Contains a carbon-carbon double bond / contains a C=C bond

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