9701 MCQ Solution 36

Question 36: [Inorganic > Nitrogen and Sulfur]:

Ammonia and chlorine react in the gas phase.

8NH₃ + 3Cl₂ à N₂ + 6NH₄Cl

Which statements are correct?

1 Ammonia behaves as a reducing agent.

2 Ammonia behaves as a base.

3 The oxidation number of the hydrogen changes.

Reference: Past Exam Paper – November 2002 Paper 1 Q36

Solution 36:

Answer: B.

The chlorine atoms change oxidation state from 0 to -1 which is reduction hence ammonia has caused reduction and 1 is correct. 

A base is a proton (H⁺) acceptor and ammonia does this when becoming an ammonium ion in the ammonium salt, thus 2 is also correct. 

Oxidation number of hydrogen does not change; in ammonia: +1, in salt: +1, thus 3 is incorrect and the correct option is B.