The nitride salt of Ca when treated with ${{H}_{2}}O$ gives:
(a)- ${{N}_{2}}$
(b)- $CaO$
(c)- $Ca{{H}_{2}}$
(d)- $N{{H}_{3}}$

Hint: The nitride salt of Ca, Calcium nitride is the inorganic compound with the chemical formula $C{{a}_{3}}{{N}_{2}}$. Now try to find its reaction with ${{H}_{2}}O$.

Complete Solution :
Calcium is the element of group 2 having atomic number 20 of the s-block, so it is a metal which is soft in texture therefore, we can say that calcium is a silvery-white metal. There is a protective thin layer on the calcium metal which protects the metal when it gets attacked by the air. There is formation of calcium oxide having formula $CaO$ and calcium nitride having formula $C{{a}_{3}}{{N}_{2}}$ when the calcium is burnt in the air. Both the reactions in which calcium oxide and calcium nitride is formed is given below:
$2Ca(s)+{{O}_{2}}(g)\to 2CaO(s)$
$3Ca(s)+{{N}_{2}}(g)\to C{{a}_{3}}{{N}_{2}}(s)$

Calcium nitride reacts with water or even the moisture in the air to give ammonia and calcium hydroxide. The chemical equation involved in this process is given below:
$C{{a}_{3}}{{N}_{2}}+6{{H}_{2}}O\to 3Ca{{(OH)}_{2}}+2N{{H}_{3}}$
So, the correct answer is “Option D”.

Additional information: We should also know that calcium nitride absorbs hydrogen above ${{350}^{\circ }}C$ . We can write the chemical equation as given below:
$C{{a}_{3}}{{N}_{2}}+2{{H}_{2}}\to 2CaNH+Ca{{H}_{2}}$

Note: We should know that elementary calcium reacts with water at room temperature, according to the following reaction mechanism, which is given below:
$Ca(s)+2{{H}_{2}}O(g)\to Ca{{(OH)}_{2}}(aq)+{{H}_{2}}(g)$

So from the reaction we can see that there is formation of calcium hydroxide whose formula is $Ca{{(OH)}_{2}}$ which can be dissolved in water to form soda.