Law of combining volumes was given by

In the reaction, ${\mathrm{N}}_2+3{\mathrm{H}}_2⟶2{\mathrm{NH}}_3,$ ratio by volume of ${\mathrm{N}}_2,{\mathrm{H}}_2$ and ${\mathrm{NH}}_3$ is $1:3:2.$ This suggested law is

Which of the following statement is correct about the reaction given below?

$4\mathrm{Fe}\left(\mathrm{s}\right)+3{\mathrm{O}}_2⟶2{\mathrm{Fe}}_2{\mathrm{O}}_3 \left(\mathrm{g}\right)$

If $2.0 \mathrm{g}$ of the hydrogen reacts with $16.0 \mathrm{g}$ of oxygen to form $18.0 \mathrm{g}$ of water, which of the following laws is applicable?

Which of the following is the best example of the law of conservation of mass?