What is molar mass?

The equation of state for $5 \, g$ of oxygen at a pressure $P$ and temperature $T$,when occupying a volume $V$,will be (where $R$ is the gas constant).

$A$ container holds $1$ mole of $O_2$ (molar mass $32$) at temperature $T$. The pressure is $P$. Another identical container holds $1$ mole of $He$ (molar mass $4$) at temperature $2T$. Find the pressure in the second container.

The $PV$ versus $T$ graph for equal masses of $H_2, He$,and $O_2$ is shown in the figure. Choose the correct alternative:

$A$ cylindrical tube of cross-sectional area $A$ has two airtight,frictionless pistons at its two ends. The pistons are tied with a straight piece of metallic wire. The tube contains a gas at atmospheric pressure $P_0$ and temperature $T_0$. If the temperature of the gas is doubled,then the tension in the wire is:

The expansion of an ideal gas of mass $m$ at a constant pressure $P$ is given by the straight line $B$. Then the expansion of the same ideal gas of mass $2\, m$ at a pressure $2\,P$ is given by the straight line