Question

Arrange these compounds in order of increasing standard molar entropy at 25°C:   

C₄H₁₀(g), C₂H₄(g), ZnS(s), and H₂O(l).

Answer 1

order of increasing standard molar entropy change at 25°C is as follows

the solid have less standard molar entorpy than liquid

liquid have less standard molar entorpy than gas

so gases state molecule have highest standard molar entorpy.

it is also typical for a molecule with more atoms like C4H10(g) to have more entropy than molecules with less atoms, like C2H4(g)

so increasing order for standard molar entorpy is

C4H10(g) = 310.23 j/mol-K , C2H4(g) =219.5 j/mol-K,H2O(l) =69.9 j/mol-K , and ZnS(s) = 57.7 J/mol-K

C4H10(g) > C2H4(g) > H2O(l) > ZnS(s)