Vapour density of a gas is $22$. What is its molecular mass?

What are the equivalent weights of $H_3PO_4$ in the following reactions respectively?
$H_3PO_4 + OH^{-} \rightarrow H_2PO_4^{-} + H_2O$
$H_3PO_4 + 2OH^{-} \rightarrow HPO_4^{2-} + 2H_2O$
$H_3PO_4 + 3OH^{-} \rightarrow PO_4^{3-} + 3H_2O$

Elements $X$ and $Y$ form compounds $X_2Y_3$ and $X_3Y_4$ respectively. If $0.2 \ mol$ of $X_2Y_3$ weighs $32.0 \ g$ and $0.4 \ mol$ of $X_3Y_4$ weighs $92.8 \ g$,then the atomic masses of $X$ and $Y$ are respectively:

What is the mass of one molecule of the compound $C_{60}H_{122}$ in grams?

$0.126 \ g$ of an acid is needed to completely neutralise $20 \ mL$ of $0.1 \ N$ $NaOH$ solution. The equivalent weight of the acid is:

If $1.2 \, g$ of a metal displaces $1.12 \, L$ of hydrogen at $STP$,the equivalent weight of the metal would be: