Chemistry 5070 · O Level

Carboxylic acids

32 practice questions on Carboxylic acids, with worked solutions and instant marking.

Which of the following has not been produced by reacting a carboxylic acid with an alcohol?

May/June 2015

Which of the following is not produced by reacting a carboxylic acid with an alcohol?

May/June 2015

Which statement concerning ethanoic acid is correct?

May/June 2016

An organic compound, X, has molecular formula $\text{C}_4\text{H}_8\text{O}_2$ and changes damp, blue litmus paper to red. What structural formula does X have?

May/June 2017

Both ethanoic acid and butanoic acid belong to the carboxylic acids.

May/June 2017

A sample of ethanoic acid, $\text{CH}_3\text{COOH}$, may be made using the apparatus illustrated.

May/June 2017

A carboxylic acid with molecular formula $\text{C}_4\text{H}_8\text{O}_2$ reacts with an alcohol with molecular formula $\text{C}_3\text{H}_8\text{O}$ to produce an ester. What might the formula of the ester produced be?

May/June 2018

The diagram illustrates the structure of oxalic acid. Which alcohol is oxidised to produce oxalic acid?

May/June 2018

Some characteristics of compound $J$ are given. • It reacts with potassium carbonate, forming carbon dioxide. • It reacts with ethanol, producing a sweet-smelling liquid. • It reacts with sodium hydroxide, forming a salt. What could be the identity of $J$?

May/June 2018

An ester is represented by the formula $\text{C}_2\text{H}_5\text{COO}\text{C}_2\text{H}_5$. Which two compounds would combine to make this ester?

May/June 2021

Which of the following statements about carboxylic acids is correct?

May/June 2022

An ester structure is illustrated. Which two compounds react together to make this ester?

May/June 2023

Fig. 8.1 shows a flow chart summarising several reactions of an organic compound. Compound A is butan-1-ol. In the presence of an acid catalyst, A reacts with ethanoic acid to produce ester B. A is oxidised with $\text{KMnO}_4(\text{aq})/\text{H}_2\text{SO}_4(\text{aq})$ to give compound C. Compound C is shown as a displayed formula with a four-carbon chain and a carboxylic acid group. C reacts with $\text{Na}_2\text{CO}_3(\text{aq})$ to produce D, gas E and liquid F. C also reacts with $\text{NaOH}(\text{aq})$ to give D and liquid F. When C reacts with $\text{CH}_3\text{CH}_2\text{OH}(\text{l})$ in the presence of an acid catalyst, ester G is formed.

May/June 2024

The diagram illustrates the structure of a compound named ethanoic anhydride. When $1\ \text{mol}$ of ethanoic anhydride reacts with water, $2\ \text{mol}$ of a carboxylic acid are produced only. This carboxylic acid then reacts with ethanol to make an ester. How many moles of water react with $1\ \text{mol}$ of ethanoic anhydride, and what is the structure of the ester?

May/June 2025

Ethanoic acid, CH$_3$COOH, belongs to the homologous series of carboxylic acids.

May/June 2025

Coal is a blend of carbon compounds containing a small quantity of sulfur. The sample of coal is heated without air in the apparatus shown. The distillate is a mixture made up of a colourless liquid and tar.

Oct/Nov 2015

A student oxidises ethanol to ethanoic acid using acidified aqueous potassium manganate(VII).

Oct/Nov 2016

Which alcohol and which acid react with one another to form the ester $\text{CH}_3\text{COO}\text{C}_2\text{H}_5$?

Oct/Nov 2017

Ethanoic acid counts as a weak acid.

Oct/Nov 2017

An ester is made when a carboxylic acid reacts with an alcohol. In what way do the numbers of carbon, hydrogen and oxygen atoms in an ester compare with the combined numbers of these atoms in the carboxylic acid and alcohol used to make it?

Oct/Nov 2018

Which two compounds combine to produce $\text{CH}_3\text{CH}_2\text{COOCH}_3$?

Oct/Nov 2019

Butanoic acid, $\text{C}_3\text{H}_7\text{COOH}$, belongs to the carboxylic acid family.

Oct/Nov 2019

Aqueous glucose is fermented using yeast at $37\,^{\circ}\text{C}$ without the presence of air. The principal organic product, X, is then separated by fractional distillation. Next, X is oxidised by heating under reflux with acidified potassium manganate(VII), producing the final product Y. Which substance is Y?

Oct/Nov 2020

The diagram illustrates the structure of a compound named ethanoic anhydride. $1\ \text{mol}$ of ethanoic anhydride reacts with water to produce only $2\ \text{mol}$ of a carboxylic acid. This carboxylic acid then reacts with ethanol to produce an ester. What number of moles of water react with $1\ \text{mol}$ of the ethanoic anhydride, and what is the ester structure?

Oct/Nov 2020

Methanoic acid and ethanoic acid belong to the group of weak acids.

Oct/Nov 2020

Which statement concerning carboxylic acids is correct?

Oct/Nov 2021

The structural formula for angelic acid is displayed.

Oct/Nov 2021

An organic compound, X, has a molecular formula $\text{C}_4\text{H}_8\text{O}_2$ and changes damp blue litmus paper to red. What is the displayed formula of X?

Oct/Nov 2024

Propanoic acid may be written using the formula $\text{CH}_3\text{CH}_2\text{COOH}$.

Oct/Nov 2024

Which of the following statements about carboxylic acids is correct?

Oct/Nov 2025

Which structure represents the carboxylic acid with the smallest relative molecular mass?

Oct/Nov 2025

Fig. 8.1 presents the displayed formula for an unsaturated carboxylic acid, X: $CH_3CH=CHCOOH$.

Oct/Nov 2025