Keeping temperature constant,the pressure of $11.2 \ dm^3$ of a gas was increased from $105 \ kPa$ to $420 \ kPa$. What is the new volume of the gas (in $dm^3$)?

The $S.I.$ unit of the gas constant $R$ is:

At $0\, ^\circ C$,$4\, g$ of $O_2$ and $2\, g$ of $H_2$ are filled in a $1\, L$ bulb. What will be the total pressure of the mixture (in $, atm$)?

The density of Neon will be highest at

An $LPG$ (Liquefied Petroleum Gas) cylinder weighs $15.0 \ kg$ when empty. When full, it weighs $30.0 \ kg$ and shows a pressure of $3.0 \ atm$. In the course of usage at $27^{\circ}C$, the mass of the full cylinder is reduced to $24.2 \ kg$. The volume of the used gas in cubic metre at the normal usage condition ($1 \ atm$ and $27^{\circ}C$) is (assume $LPG$ to be normal butane and it behaves ideally). (in $m^3$)

If the initial volume of a neon gas is reduced by $15\%$ upon cooling to $75\,^\circ C$,to what temperature in $^\circ C$ should it be heated so that the pressure becomes double?