Nelson cell is used for the preparation of

$A$ chloride salt dissolves appreciably in cold water. When placed on a platinum wire in a Bunsen flame,no distinctive color is noted. Which cation could be present?

The metal which gives hydrogen on treatment with acid as well as sodium hydroxide is

$A$ metal $M$ reacts with $N_2$ to form a compound $A$ $(M_3N)$. Heating $A$ at a high temperature gives back $M$,and passing $A$ through $H_2O$ results in the evolution of gas $B$. Gas $B$ turns $CuSO_4$ solution blue. What are $A$ and $B$ respectively?

The decomposition of sodium nitrate at temperatures above $800 \, ^oC$ yields ...............

Identify the incorrect reaction from the following.