$A$ sample of calcium carbonate $(CaCO_3)$ has the following percentage composition: $Ca = 40\%$,$C = 12\%$,$O = 48\%$. If the Law of Definite Proportions is true,what is the weight of calcium in a $4 \ g$ sample of calcium carbonate?

$n \ g$ of substance $X$ reacts with $m \ g$ of substance $Y$ to form $p \ g$ of substance $R$ and $q \ g$ of substance $S$. This reaction can be represented as,$X + Y \rightarrow R + S$. The relation which can be established in the amounts of the reactants and the products will be

Among the following pairs of compounds,the one that illustrates the law of multiple proportions is

Which of the following pairs of compounds cannot demonstrate the law of multiple proportions?

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?

$A$ sample of pure carbon dioxide,irrespective of its source,contains $27.27\%$ carbon and $72.73\%$ oxygen. This data supports: