When a metal X is treated with cold water, it gives a basic salt Y with molecular formula XOH (Molecular mass = 40) and liberates a gas Z which easily catches fire. Identify X, Y and Z and also write the reaction involved.
X is sodium because molar mass of NaOH is 40; which can be shown as follows:
Na (23) + O(16) + H (1) = 40
So, Y is NaOH
Z is hydrogen gas which easily catches fire.
Reaction between sodium and water can be given as follows:
2Na + 2H2O → 2 NaOH + H2
