$A$ gas is filled in a cylinder. If its temperature is increased by $20\%$ and its volume decreases by $10\%$, what percentage of the gas will have leaked out?

The pressure of a given mass of gas at $20^{\circ}C$ is $P$. At constant volume,at what temperature in $^{\circ}C$ will the pressure of the gas become $2P$?

The figure shows the pressure $P$ versus volume $V$ graphs for two different gas samples at a given temperature. $M_A$ and $M_B$ are the masses of the two samples,and $n_A$ and $n_B$ are the numbers of moles. Which of the following must be incorrect?

What is the number of molecules in $1 \, litre$ of an ideal gas at $S.T.P.$?

In the figure,the volume of container $X$ is twice the volume of container $Y$. Both contain an ideal gas. The temperature of $X$ is $200 \, K$ and the temperature of $Y$ is $400 \, K$. If the mass of the gas in $X$ is $m$,what will be the mass of the gas in $Y$?

$A$ container $A$ contains a gas at pressure $P$,volume $V$,and temperature $T$. Another container $B$ contains a gas at pressure $2P$,volume $V/4$,and temperature $2T$. The ratio of the number of molecules in container $A$ to that in container $B$ is: