Which law is illustrated by compounds $H_2O$ and $H_2O_2$ formed from two different elements,$H$ and $O$?

$A$ sample of calcium carbonate has the following percentage composition: $Ca = 40 \%$,$C = 12 \%$,and $O = 48 \%$. According to the law of definite proportion,the weight of calcium in $4 \ g$ of a sample of calcium carbonate from another source will be (atomic weights: $Ca = 40, C = 12, O = 16$).

$45.4 \ L$ 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.

Carbon and oxygen form two known compounds. One compound contains $42.9\%$ carbon,while the other contains $27.3\%$ carbon. This illustrates the law of:

What weight of $BaCl_2$ is required to react with $24.4 \ g$ of sodium sulfate to produce $46.6 \ g$ of barium sulfate and $23.4 \ g$ of sodium chloride (in $g$)?

Which of the following statements is correct about the given reaction?
$4Fe_{(s)} + 3O_{2_{(g)}} \to 2Fe_{2}O_{3_{(s)}}$