What is molar volume? Write its $SI$ unit.

$Assertion :$ One mole of any substance at any temperature or volume always contains $6.02 \times 10^{23}$ molecules.
$Reason :$ One mole of a substance always refers to $S.T.P.$ conditions.

An engineer is given a fixed volume $V_m$ of metal with which to construct a spherical pressure vessel. Assuming the vessel has thin walls and is pressurized to its bursting point,the amount of gas the vessel can contain,$n$ (in moles),depends only on $V_m$ $(m^3)$,the temperature $T$ $(K)$,the ideal gas constant $R$ $(J/(K \cdot mol))$,and the tensile strength of the metal $\sigma$ $(N/m^2)$. Which of the following gives $n$ in terms of these parameters?

In the given pressure $(P)$ - absolute temperature $(T)$ graph of an ideal gas,the relation between volumes $V_1, V_2, V_3$ and $V_4$ is

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

The graph shows the $PV$ vs $P$ plot for different gases at a constant temperature. Which graph represents an ideal gas?