Who proposed the Law of Multiple Proportions?

Explain the Law of Multiple Proportions.

According to Dalton’s atomic theory,an atom

Hydrogen peroxide and water contain $5.93\%$ and $11.2\%$ of hydrogen,respectively. Which law is illustrated by this data?

When $2.16 \ g$ of metallic copper is treated with nitric acid,the weight of copper oxide obtained is $2.70 \ g$. In a second experiment,$1.15 \ g$ of copper oxide on reduction gives $0.92 \ g$ of copper. These results illustrate the law of:

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 $P_2 Q$.