Which of the following pairs of atomic numbers represents elements belonging to the $s$-block?

Which of the following is $NOT$ obtained when metal carbides react with $H_2O$?

Assertion : $Al(OH)_3$ is insoluble in $NH_4OH$ but soluble in $NaOH$.
Reason : $NaOH$ is a strong alkali.

Which of the following substances is used as a fertilizer?

$A$ hydrated solid $X$ on heating initially gives a monohydrated compound $Y$. $Y$ upon heating above $373 \ K$ leads to an anhydrous white powder $Z$. $X$ and $Z$,respectively,are

On heating $ZnCl_2 \cdot 2H_2O$,the compound obtained is