Question

Part A - Calculating ΔS∘ from Tabulated Entropies Using the standard molar entropies below, calculate the standard entropy change, ΔS∘ , for the "water-splitting" reaction at 298 K: 2H2O(l) → 2H2(g) + O2(g) Standard Molar Entropies of Selected Substances at 298 K Substance S∘ (J/mol⋅K) H2(g) 130.6 O2(g) 205.0 H2O(g) 188.8 H2O(l) 69.9 Using the standard molar entropies below, calculate the standard entropy change, , for the "water-splitting" reaction at 298 : Standard Molar Entropies of Selected Substances at 298 Substance () 130.6 205.0 188.8 69.9 326.4 J/K 265.7 J/K 163.2 J/K 88.5 J/K −326.3 J/K

Answer 1

Answer:

The standard entropy or reaction ΔS° =+324.6J/mol.K

Explanation:

The reaction is

2H2O(l) → 2H2(g) + O2(g)

Standard Molar Entropies of Selected Substances at 298 K are

Substance S∘ (J/mol⋅K)

H2(g) 130.6

O2(g) 205.0

H2O(g) 188.8

H2O(l) 69.9

The standard entropy of reaction will be obtained from standard entropy of formation as given below

ΔH°= 2(130.6)+(205.0)-2(69.9) (Jol/mol.K)

ΔH°=261.2+205.0-139.8

ΔH°=+324.6Jol/mol.K