Test Index

JAMB Chemistry 2010 Paper

Question : 17

Total: 49

The acid that is used to remove rust is?

Solution:

Concept:

Rust is iron(III) oxide, which reacts with acids to form soluble iron salts.

Explanation:

Rust is mainly

\mathrm{Fe}_2\mathrm{O}_3 \cdot x\mathrm{H}_2\mathrm{O}

Hydrochloric acid reacts readily with rust to dissolve it:

\mathrm{Fe}_2\mathrm{O}_3 + 6\mathrm{HCl} \rightarrow 2\mathrm{FeCl}_3 + 3\mathrm{H}_2\mathrm{O}

It is commonly used for rust removal because the iron(III) chloride formed dissolves in water.

Answer:

B. hydrochloric

Go to Question:

Prev Question

Next Question