Answer: 141.55 J/K
Explanation: Value of ΔS can be obtained as:
[tex]\Delta S=\sum{\text {Entropy of Products}-\sum{\text {Entropy of Reactants}}[/tex]
Standard entropy values are
[tex]S^o(Fe_2O_3)=87.4J/molK[/tex]
[tex]S^o(H_2)=130.59J/molK[/tex]
[tex]S^o(Fe)=27.28J/molK[/tex]
[tex]S^o(H_2O)=188.72J/molK[/tex]
[tex]Fe_2O_3(s)+3H_2(g)\rightarrow 2Fe(s)+3H_2O(g)[/tex]
[tex]\Delta S=\sum(2\times 27.28J/molK+3\times 188.72J/molK)-(3\times 130.59J/molK+1\times 87.4J/molK)=141.55J/K[/tex]
