higher molar entropies

[CNourian2H]

why does a monoatomic gas have higher entropy than a diatomic gas?

[BNgo_2L]

Monoatomic gases can occupy more space, so more disorder would occur than diatomic gases, which consist of two bonded atoms (more order).

[MeeraBhagat]

Monoatomic gases have the potential to occupy more positions than a diatomic gas, and this would cause the degeneracy term for a monoatomic gas to be higher than a diatomic gas. Given the relationship between degeneracy and entropy, this would lead to a higher entropy for a monoatomic gas.