The difference between standard molar entropies of two mono-atomic gases (A) and (B) $\left(\mathrm{S}_{\mathrm{m}, \mathrm{A}}^{0}-\mathrm{S}_{\mathrm{m}, \mathrm{B}}^{0}\right)$ at a given temperature is (given that the molar mass of (A) is twice the molar mass of (B)
(a)$\frac{3}{2} R \ln 2$
(b)$R \ln 2$
(c)$\frac{5}{2} R \ln 2$
(d)$\frac{7}{2} R \ln 2$
Answer
Answer: A ✓ checked by 4AB · confidence high
Explanation
From Sackur–Tetrode, S_m depends on (3/2)R ln M. Doubling M gives ΔS = (3/2)R ln 2 (a).