Question

A silvery-white metal $X$ reacts with water at room temperature to produce a water-soluble compound $Y$ and a colourless gas $Z$. The reaction is highly exothermic and the $Z$ catches fire immediately during the reaction. The solution of $Y$ in the water on reacting with a stoichiometric amount of dilute solution of hydrochloric acid gives a solution of $pH=7.0$.
The compounds $X,Y$ and $Z$ respectively are:

• A. $Al,Al(OH{)}_3$ and $H_2$
• B. Ag, AgOH and $H_2$
• C. K, KCl and $H_2$
• D. Na, NaOH and $H_2$

Answer 1

Answer: (D)

Na, NaOH and $H_2$

$2Na+H_{2}O\to 2NaOH+H_2+Heat$

$NaOH+HCl\to NaCl+H_{2}O$

$X,Y,Z$ are $Na$, $NaOH$, $H_2$