Black oxide of copper and red oxide of copper contain $79.9\%$ and $88.8\%$ of metal respectively. This data illustrates the law of:

$45.4 \ L$ of dinitrogen reacts with $22.7 \ L$ of dioxygen to form $45.4 \ L$ of nitrous oxide. For the reaction $2N_{2(g)} + O_{2(g)} \to 2N_2O_{(g)}$,identify the law followed and state the law.

The following data are obtained when dinitrogen and dioxygen react together to form different compounds:

Mass of dinitrogen	Mass of dioxygen
$14 \ g$	$16 \ g$
$14 \ g$	$32 \ g$
$28 \ g$	$32 \ g$
$28 \ g$	$80 \ g$

Which law of chemical combination is obeyed by the above experimental data?

To check the principle of multiple proportions,a series of pure binary compounds $(P_m Q_n)$ were analyzed and their composition is tabulated below. The correct option$(s)$ is(are)

Compound	Weight $\%$ of $P$	Weight $\%$ of $Q$
$1$	$50$	$50$
$2$	$44.4$	$55.6$
$3$	$40$	$60$

$(A)$ If empirical formula of compound $3$ is $P_3 Q_4$,then the empirical formula of compound $2$ is $P_3 Q_5$.
$(B)$ If empirical formula of compound $3$ is $P_3 Q_2$ and atomic weight of element $P$ is $20$,then the atomic weight of $Q$ is $45$.
$(C)$ If empirical formula of compound $2$ is $PQ$,then the empirical formula of the compound $1$ is $P_5 Q_4$.
$(D)$ If atomic weight of $P$ and $Q$ are $70$ and $35$,respectively,then the empirical formula of compound $1$ is $P_2 Q$.

Zinc sulfate crystals contain $22.65\%$ of zinc and $43.9\%$ of water. If it follows the law of definite proportions,how many grams of $Zn$ are required to obtain $20 \, g$ of crystals?

Statement $1$: Creation or destruction of atoms is not possible.
Statement $2$: Under identical conditions of temperature and pressure,the number of atoms/molecules in a given volume of gas is not the same.