Question

What is ∆H for the reaction of sulfur dioxide with oxygen?


2SO2(g) + O2(g) → 2SO3(g)


(∆Hf0 SO2(g) = –296.8 kJ/mol; ∆Hf0 SO3(g) = –395.7 kJ/mol)

A.)–98.9 kJ

B.)–197.8 kJ

C.)1.385 × 103 kJ

D.)197.8 kJ

Answer 1

Answer:

B.) –197.8 kJ

Balanced equation : 2SO₂(g) + O₂(g) → 2SO₃(g)

Given:

• SO₂(g) = –296.8 kJ/mol

• SO₃(g) = –395.7 kJ/mol

================================================================

• products : 2 ( –296.8 ) + O₂ = -593.6 kJ/mol + O₂

• reactant : 2 (  –395.7 ) = -791.4 kJ/mol

products energy = reactant energy

-593.6 + O₂ = -791.4

O₂ = -791.4 - ( -593.6)

O₂ = –197.8 kJ