Question

For the reaction CO(g) + (1)/(2)textO₂(textg) → textCO₂(textg), which one of the statements is correct at constant T and P?

• A. Δ H = Δ E
• B. Δ H < Δ E
• C. Δ H > Δ E
• D. Δ H is independent of physical state of the reactants

Hint:

If number of gaseous moles decreases during reaction, then: Δ H < Δ E

Answer 1

The Correct Option is B

Step 1: Relation between enthalpy and internal energy: Δ H = Δ E + Δ ng RT 

Step 2: For the reaction: Δ ng = (1) - (1 + (1)/(2)) = -(1)/(2) 

Step 3: Since Δ ng < 0: Δ H < Δ E