In $LiAlH_4$,metal $Al$ is present in

The alkali metals form salt-like hydrides by direct synthesis at elevated temperatures. The thermal stability of these hydrides decreases in which of the following orders?

$NH_3 + CO_2 + H_2O \to A$
$A + H_2O + CO_2 \to B$
$B + NaCl \to C + NH_4Cl$
$C \xrightarrow{\Delta} D + H_2O + CO_2$
Identify the incorrect statement.

Match column $-I$ with column $-II$ :

Column $-I$	Column $-II$
$(a).$ Spodumene	$(p).$ $K$
$(b).$ Borax	$(q).$ $Na$
$(c).$ Sylvine	$(r).$ $Li$
$(d).$ Chile saltpetre	$(s).$ $Ca$

Assertion : $K$,$Rb$ and $Cs$ (all belonging to group $1$) can also form superoxides.
Reason : The ionic radii of $K$,$Rb$ and $Cs$ show the following trend $Cs^{+} < Rb^{+} < K^{+}$.

Give short explanations on salts of oxo-acids of alkali metal elements.