◈ Oracle PrepSign Up Free
A-LevelChemistryGroup 29701/12 · Oct/Nov 2021 · Q191 Mark

Magnesium hydroxide dissolves in aqueous ammonium chloride, but not in aqueous sodium chloride. Which statement explains this observation?

AThe ionic radius of the NH4⁺ ion is similar to that of Mg²⁺ but not that of Na⁺.
BNH4Cl dissociates less fully than NaCl.
CThe Na⁺ and Mg²⁺ ions have the same number of electrons.
DThe NH4⁺ ion can donate a proton.

✓ Correct answer

D: The NH4⁺ ion can donate a proton.

Practise more questions on this topic

Oracle Prep sorts past-paper questions by topic, so you can drill Group 2 and see which topics are most likely to come up next.

Sign up free →

About this question

Topic
Group 2, A-Level Chemistry (syllabus 9701). Multiple choice, 1 mark.
Source
A-Level Chemistry, Oct/Nov 2021 Paper 1 Variant 2, question 19.

Questions and mark schemes are from past examination papers and remain the copyright of the exam board. How Oracle Prep builds its content

Related Chemistry questions

Group 2Feb/Mar 20231m

Four properties of beryllium, Be, or a beryllium compound are listed. Which property is different from the property o…

Group 2Feb/Mar 202311m

The Group 2 elements Mg to Ba are all silvery-white reactive metals.

Group 2Feb/Mar 20241m

Separate samples of magnesium and calcium are added to an excess of dilute sulfuric acid. The observations are summar…

Atomic structureFeb/Mar 20221m

What is the electronic configuration of Mg²⁺?

Atoms, molecules and stoichiometryFeb/Mar 20221m

Compound X contains the elements C, H and O only. 2.00 g of X produces 4.00 g of carbon dioxide and 1.63 g of water w…

Chemical bondingFeb/Mar 20221m

For which molecule is the dipole moment zero?

← Browse all past-paper questions

© 2026 Oracle Prep