Answer to Question #288303 in Molecular Physics | Thermodynamics for harry

Question

Determine change of entropy for a reaction: H2(g) + I2(g) → 2HI(g)

H2(g) - 130.58 I2(J/mol.K)

I2 - 116.73(J/mol.K)

HI(g) - 206.3(J/mol.K) 

Answer 1

$H_2+I_2\rightarrow2HI$

$∆S°_{rxn}=2S(HI)-[S(H_2)+S(I_2)]$

Put value

$∆S°_{rxn}=2\times206.3-[(130.58+116.73)]$

$∆S°_{rxn}=(412.6-247.31)J/K$

$∆S°_{rxn}=165.29J/K$