When NaOH reacts with metal a X, the following reaction takes place:
NaOH+X→Na2ZnO2+Y
Identify X and Y.
X is Zn and Y is H2
2NaOH+Zn→Na2ZnO2+H2
When a base reacts with a metal it liberates hydrogen gas. Zinc reacts with sodium hydroxide to produce sodium zincate and hydrogen gas. This reaction takes place at a temperature of about 5500C.