Name the gas evolved when NaOH reacts with zinc.
Zinc is a transition element and it shows amphoteric nature which means that zinc can react as an acid as well as a base to form corresponding amphoteric oxides or hydroxides.
So when zinc reacts with sodium hydroxide, it forms sodium zincate and hydrogen gas is evolved. The reaction is as follows:
Zn + 2NaOH → Na2ZnO2 + H2