Question

At constant temperature and pressure which one of the following statements is correct for the reaction

CO(g) + 1/2O₂(g) → CO₂(g)

• A. ∆H = ∆E
• B. ∆H <∆E
• C. ∆H >∆E
• D. ∆H is independent physical state of reactant

Answer 1

Answer: (B)

∆H <∆E

Answer 2

As we know,

∆H = ∆E + ∆nRT

Where ∆n = Gaseous product moles – gaseous reactant moles

For the reaction,

CO(g) + 1/2O₂(g) → CO₂(g)

∆n = 1–(1+1/2) = –1/2

∴∆H = ∆E – 1/2 RT

∴ ∆H <∆E