In Solvay process, $\mathrm{NH}_3$ is recovered when the solution containing $\mathrm{NH}_4 \mathrm{Cl}$ is treated with compound ' $X$ '. What is ' $X^{\prime}$ ?

Identify the correct statements from the following.

I. All alkaline earth metals give hydrides on heating with hydrogen.

II. Calcium hydroxide is used to purify sugar.

Identify the correct statement from the following.

A. Among alkali metal ions, $\mathrm{Li}^{+}$has highest hydration enthalpy.

B. Boiling point of alkali metals increases from Li to Cs .

C. Density of K is less than that of Na and Rb .

D. Li has strong tendency to form superoxide.

The correct answer is

Consider the following

Statement - I : Both $\mathrm{BeSO}_4$ and $\mathrm{MgSO}_4$ are readily soluble in water.

Statement - II : Among the nitrates of alkaline earth metals, only $\mathrm{Be}\left(\mathrm{NO}_3\right)_2$ on strong heating gives its oxide, $\mathrm{NO}_2$ and $\mathrm{O}_2$.

The correct answer is