$A$ $2.24\,L$ oxygen cylinder shows a leakage at $NTP$. When the leakage is plugged,the pressure drops by $570\,mm\,Hg$. What is the number of moles of gas that escaped?

$A$ certain mass of gas occupies a volume of $2 \ L$ at $STP$. If the pressure is kept constant,what will be the temperature in $^\circ C$ for the gas to occupy a volume of $4 \ L$?

At $300 \ K$ temperature and $1 \ atm$ pressure,the weight of $1 \ L$ of a gas is $2 \ g$. If the pressure is changed to $0.75 \ atm$,at what temperature in $K$ will the weight of $1 \ L$ of the same gas be $1 \ g$?

Pay load is defined as the difference between the mass of displaced air and the mass of the balloon. Calculate the pay load when a balloon of radius $10 \, m$,mass $100 \, kg$ is filled with helium at $1.66 \, bar$ at $27^{\circ} C$. (Density of air $= 1.2 \, kg \, m^{-3}$ and $R = 0.083 \, bar \, dm^{3} \, K^{-1} \, mol^{-1}$).

The temperature at which $4 \ mol$ of a gas occupies $5 \ dm^3$ volume at $3.32 \ bar$ pressure is:

The following $P$ vs $V$ curve is plotted. What is the relation between $T_1$,$T_2$ and $T_3$?