At 0 degC the Z versus P curves of CH4 and N2 both show minima. Given a(CH4) = 2.25, a(N2) = 1.39 (in L^2 atm mol^-2) and b nearly equal, which statement is correct?

The minimum for CH4 is deeper and occurs at lower Z

Both minima have the same depth because b is the same

Neither gas shows a minimum at 0 degC

JEE Advanced levelSingle correct optionDifficulty 3 of 3rg174

At $0^{\circ} C$ the $Z$ versus $P$ curves of $CH X_{4}$ and $N X_{2}$ both show minima. Given $a (CH X_{4}) = 2.25$ , $a (N X_{2}) = 1.39$ (in $L^{2} atm mo l^{- 2}$ ) and $b$ nearly equal, which statement is correct?

The depth of the minimum is governed by how much

a / RT

exceeds

b

. With similar

b

, the gas with larger

a

(methane) has the larger negative initial slope and a deeper dip in

Z

. Both are below their Boyle temperatures at

273 K

, so both show minima.