If in a given container there is a gas of mass $M$ and $M_{0}$ is its molar mass,then what will be the number of moles?

Temperature remaining constant,the pressure of a gas is decreased by $20 \%$. What is the percentage change in volume?

The number of molecules in $1 \, cm^{3}$ of an ideal gas at $N.T.P.$ is:

$A$ cylinder contains $10\, kg$ of gas at a pressure of $10^7\, N/m^2$. The quantity of gas taken out of the cylinder,if the final pressure is $2.5 \times 10^6\, N/m^2$,will be ..... $kg$ (Temperature of the gas is constant).

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?

Absolute zero $(0\, K)$ is that temperature at which