question_answer

Magnesium burns in air to give a white ash which when reacted with water gives smell of ammonia.

Answer:

                The white ash contains a small amount of magnesium nitride\[(M{{g}_{3}}{{N}_{2}})\] along with magnesium oxide (MgO) which are formed when magnesium burns in air. Magnesium nitride reacts with water to give characteristic smell of ammonia. \[M{{g}_{3}}{{N}_{2}}+6{{H}_{2}}O\xrightarrow{\,}\,3Mg{{(OH)}_{2}}+2N{{H}_{3}}\]