Which chloride does not exist as hydrate?

Identify the product when magnesium burns in air.

$A$ chemical $A$ is used for the preparation of washing soda to recover ammonia. When $CO_2$ is bubbled through an aqueous solution of $A$,the solution turns milky. It is used in white washing due to its disinfectant nature. What is the chemical formula of $A$?

Which of the following compounds is obtained as a by-product in the synthesis of sodium carbonate by the Solvay process?

Fill in the blanks:
$(1)$ $Li-Mg$ alloy is used to prepare ......
$(2)$ Colors of superoxides of alkali metals are ...... or ......
$(3)$ On combustion of lithium in the presence of air,it produces ...... and ......
$(4)$ On heating,lithium nitrate converts into ......

On dissolving a moderate amount of sodium metal in liquid $NH_3$ at low temperature,which one of the following does not occur?