Calucalculate standard entropy change in the reaction
Fe2O3(s) + 3H2(g) → 2Fe(s) + 2H2O(1)
Given: Som(Fe2O3,S) = 87.4, Som(Fe,S) = 27.3
Som(H2,g) = 130.7, Som(H2O,1)= 69.9 JK−1mol2
-215.2 JK-1
Fe2O3(s) + 3H2(g) → 2Fe(s) + 3H2O(s)
Changed balanced equation
ΔS = ∑ S0(Products) − ∑ S0(Reactants)
[2S0Fe + 2S0H2O] − [S0Fe2O3 + 3S0H2]
= (2 × 27.3 + 3 × 69.9) − [87.4 + 3 × 130.7] = (54.6 + 209.7) − [87.4 + 92.1]
= 264.3 − 479.5 = −215.2 J/K/mol