For the reaction C₂ H₄(g)+3 O₂(g) → 2 CO₂(g)+2 H₂ O(l), the value of Δ H-Δ U (in kJ) at 300 K and 1bar is

(a) -5.0. Explanation: ΔH − ΔU = Δngas RT = (2 − 4) × 8.314 × 300 = −5.0 kJ.

Q122 · CSIR-NET Chemistry, December 2011

Paper: CSIR-NET December 2011 · Subject: Physical Chemistry · Chapter: Thermodynamics · Topic: Thermodynamics – General · Marks: 2 · Difficulty: Medium

For the reaction $\mathrm{C}_{2} \mathrm{H}_{4}(\mathrm{g})+3 \mathrm{O}_{2}(\mathrm{g}) \rightarrow 2 \mathrm{CO}_{2}(\mathrm{g})+2 \mathrm{H}_{2} \mathrm{O}(\mathrm{l})$, the value of $\Delta \mathrm{H}-\Delta \mathrm{U}$ (in kJ ) at 300 K and 1bar is

(a)-5.0

(b)0.0

(c)2.5

(d)5.0

Answer

Answer: A ✓ checked by 4AB · confidence high

Explanation

ΔH − ΔU = Δn_gas RT = (2 − 4) × 8.314 × 300 = −5.0 kJ.

Study loop for Thermodynamics

1. Practise the PYQsPrevious-year questions, with answers

· Browse this chapter in the app