The number of molecules of $CO_2$ liberated by the complete combustion of $0.1 \ mol$ of graphite in air is

The molarity of $2 \, N \, HCl$ is .......

If $0.5 \ g$ of a mixture of two metals $A$ and $B$ with respective equivalent weights $12$ and $9$ displace $560 \ mL$ of $H_2$ at $STP$ from an acid,the composition of the mixture is:

What is the volume occupied by $2.5 \ mol$ of ammonia gas at $\text{STP}$ (in $dm^3$)?

When the same amount of zinc is treated separately with an excess of sulphuric acid and an excess of sodium hydroxide solution,the ratio of the volumes of hydrogen evolved is:

$x \ g$ of methane was burnt completely in the presence of oxygen. The liberated gases were passed into a solution containing $370 \ g$ of $Ca(OH)_2$. The weight of white precipitate obtained was $500 \ g$. What is the value of $x$ (in $g$)? (Given: $C=12, H=1, Ca=40, O=16 \ u$)