(ΔH – ΔU) for the formation of carbon monoxide (CO)

• Chemical Thermodynamics

(ΔH – ΔU) for the formation of carbon monoxide (CO) from its elements at 298 K is (R = 8.314 JK^–1 mol^–1)

1. 1238.78 J/mol
2. 2477.57 J/mol
3. –2477.57 J/mol
4. –1238.78 J/mol

Answer

ΔH – ΔU = Δn_gRT

Reaction for the formation of carbon monoxide is:

C (s) + ½O₂ (g) ⟶ CO (g)

Δn_g = 1 - 1/2 = 1/2

ΔH – ΔU = 1/2 x 8.314 x 298

= 1238.78 J/mol

The correct option is A.