Solution:
The given statement is true.Concept: Metal nitrides decompose to metal hydroxide and ammonia on treatment with water.
Nitride is an ion of nitrogen in the -3 oxidation state. Magnesium hydroxide
decomposes to its hydroxide and ammonia. This is a common reaction for metal nitrides.The reaction is as follows;
The 
can be identified by its solubility in sodium hydroxide. Both magnesium nitride and hydroxide are soluble in . While lead hydroxide dissolves in . This is used to distinguish between them.The ammonia produced can be identified by treating it with . To the gas produced, a glass rod dipped in is shown.
which produces dense white vapours of 
on this test.Hence, the correct answer is option 1.
