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 $g$)?

Two elements $x$ and $y$ have atomic masses $14$ and $16$ respectively. They form a series of five compounds $A, B, C, D, E$ in which the ratio of $x$ to $y$ is $1:2:3:4:5$. If compound $A$ contains $28$ parts by weight of $x$ and $16$ parts by weight of $y$,then in compound $C$,how many parts by weight of $x$ will combine with $24$ parts by weight of $y$?

In compound $A$,$1.00 \, g$ nitrogen unites with $0.57 \, g$ oxygen. In compound $B$,$2.00 \, g$ nitrogen combines with $2.24 \, g$ oxygen. In compound $C$,$3.00 \, g$ nitrogen combines with $5.11 \, g$ oxygen. These results obey the following law:

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

$2 \ g$ of hydrogen combine with $16 \ g$ of oxygen to form water and with $6 \ g$ of carbon to form methane. In carbon dioxide,$12 \ g$ of carbon are combined with $32 \ g$ of oxygen. These figures illustrate the law of:

Ammonia contains $82.35\%$ nitrogen and $17.65\%$ hydrogen. Water contains $88.90\%$ oxygen and $11.10\%$ hydrogen. Nitrogen dioxide contains $63.15\%$ oxygen and $36.85\%$ nitrogen. Which law can be illustrated by the given data?