Question

Ex: For the reaction: 2 SO2(g) + O2(g)  2 SO3(g) at 25C and 1 atm.,

what are delta H, delta S, and delta G, given:

deltaH delta S
SO2(g) -297 kJ/mole 248 J/moleK
SO3(g) -396 257
O2(g) 0 205

Hf S SO2(g) -297 kJ/mole 248 J/moleK SO3(g) -396 257 O2(g) 0 205

Answer 1

`Solution:- 2SO₂(g) + O₂(g) -----> 2SO₃(g)

delta H of reaction = sum of delta H of products - sum of delta H of reactants

delta H of reaction = 2mol(-396 kJ/mol) - 2mol(-297 kJ/mol

delta H of reaction = -792 kJ + 594 kJ

delta H of reaction = = -198 kJ

delta S of reaction = 2mol(257J/mol.K) - [2mol(248 J/mol.K) + 1 mol(205 J/mol.K)]

delta S of reaction = 514 J/K - 496 J/K - 205 J/K

delta S of reaction = -187 J/K

delta G of reaction = delta H - T*delta S

delta G of reaction = -198 kJ - 298K(-0.187 kJ/K)

delta G of reaction = -198 kJ + 55.7 kJ

delta G of reaction = -142 kJ