Equal masses of $H_2, O_2$ and methane have been taken in a container of volume $V$ at temperature $27 \ ^oC$ in identical conditions. The ratio of the volumes of gases $H_2 : O_2 :$ methane would be

What is the volume occupied by $0.5 \ mol$ of $CO_2$ at $STP$ (in $dm^3$)?

Magnetite can be reduced with $CO$ to yield iron metal and carbon dioxide. Calculate the mass of magnetite (in $kg$) needed to obtain $4 \ kg$ of iron if the process is $80 \%$ efficient. [Atomic weight of $Fe$ and $O$ are $56 \ g$ and $16 \ g$, respectively]

$5 \, mL$ of $N$ $HCl$,$20 \, mL$ of $N/2$ $H_2SO_4$,and $30 \, mL$ of $N/3$ $HNO_3$ are mixed together and the volume is made up to $1 \, L$. The normality of the resulting solution is:

Calculate the amount of $CO_2$ gas produced when $32 \text{ g}$ of $CH_4$ is burned with a sufficient amount of oxygen. (Given: atomic weights of $C=12, O=16, H=1$) (in $\text{ g}$)

If a $100 \ mL$ solution contains $X \ g$ of $Na_2CO_3$ and its concentration is $Y \ M$,then $X$ and $Y$ are respectively ...............