Question

Sulfuryl dichloride may be formed from the reaction of sulfur dioxide and chlorine. SO2(g) + Cl2(g) → SO2Cl2(g) Substance: SO2(g) Cl2(g) SO2Cl2(g) ΔH°f (kJ/mol) at 298 K –296.8 0 –364.0 ΔG°f (kJ/mol) at 298 K –300.1 0 –320.0 S°(J/K • mol) at 298 K 248.2 223.0 311.9 What is ΔG°rxn for this reaction at 600 K?

Answer 1

ΔG°rxn = 28.4kJ/mol at 600K

Step-by-step explanation:

Using Hess's law, you can find the ΔH°rxn and S° subtracting ΔH°f of products - ΔH°f of reactants ×its coefficients. In the same way for S°rxn

For example, for the reaction:

aA + bB → cC:

ΔH°rxn = c×ΔH°fC - (a×ΔH°fA + b×ΔH°fB).

S°rxn = c×S°fC - (a×S°fA + b×S°fB).

For the reaction:

SO₂(g) + Cl₂(g) → SO₂Cl₂(g)

ΔH°rxn = 1×ΔH°f{SO₂Cl₂} - (1×ΔH°fSO₂ + 1×ΔH°fCl₂).

S°rxn = 1×S°f{SO₂Cl₂} - (1×S°fSO₂ + 1×S°fCl₂).

As at 298K:

ΔH°f{SO₂Cl₂} = -364.0kJ/mol

ΔH°f{SO₂} = -296.8kJ/mol

ΔH°f{Cl₂} = 0kJ/mol

ΔH°rxn = 1×{-364.4kJ/mol} - (1×-296.8kJ/mol + 1×0).

ΔH°rxn = -67.2kJ/mol at 298K.

S°f{SO₂Cl₂} = 311.9J/molK

S°f{SO₂} = 248.2J/molK

S°f{Cl₂} = 223.0J/molK

S°rxn = 1×{311.9J/molK} - (1×248.2J/molK + 1×223.0J/molK).

S°rxn = -159.3J/molK = -0.159.3KJ/molK

Using:

ΔG°rxn = ΔH°rxn - S°rxn×T

Assuming ΔH°rxn doesn't change at 600K:

ΔG°rxn = -67.2kJ/mol - -0.159.3J/molK×600K

ΔG°rxn = 28.4kJ/mol at 600K