Zinc sulphate contains $22.65\%$ of zinc and $43.9\%$ of water of crystallization. If the law of constant proportions is true,then the weight of zinc required to produce $20\, g$ of the crystals will be ............. $g$.

Match the laws given in List-$A$ with the scientists who discovered them in List-$B$.

List-$A$	List-$B$
$(1)$ Law of Multiple Proportions	$(A)$ Dalton
$(2)$ Law of Conservation of Mass	$(B)$ Joseph Proust
$(3)$ Law of Definite Proportions	$(C)$ Lavoisier
	$(D)$ Hofmann

Carbon and oxygen combine to form two oxides,carbon monoxide and carbon dioxide,in which the ratio of the weights of carbon and oxygen is respectively $12 : 16$ and $12 : 32$. These figures illustrate the:

Two elements $X$ and $Y$ have atomic weights of $14$ and $16$. They form a series of compounds $A, B, C, D$ and $E$ in which for the same amount of element $X$,the amounts of $Y$ are present in the ratio $1 : 2 : 3 : 4 : 5$. If the compound $A$ has $28$ parts by weight of $X$ and $16$ parts by weight of $Y$,then the compound $C$ will have $28$ parts by weight of $X$ and:

Which of the following pairs of substances illustrate the law of multiple proportions?

Which of the following pairs of substances illustrates the Law of Multiple Proportions?