Problem: Suppose that the gas-phase reaction 2NO(g) + O2(g) → 2NO2(g) were carried out in a constant-volume container at constant temperature.(a) Would the measured heat change represent ΔH or ΔE?(b) If there is a difference, which quantity is larger for this reaction?(c) Explain your answer to part (b).

FREE Expert Solution

Internal Energy:

$\overline{){\mathbf{∆}}{\mathbf{E}}{\mathbf{=}}{\mathbf{q}}{\mathbf{+}}{\mathbf{w}}}$

Recall that work (w) is given by:

$\overline{){\mathbf{w}}{\mathbf{=}}{\mathbf{-}}{\mathbf{P\Delta V}}}$

At constant V → w = 0

$\mathbf{∆}\mathbf{E}\mathbf{=}\mathbf{q}\mathbf{+}\mathbf{0}\phantom{\rule{0ex}{0ex}}\phantom{\rule{0ex}{0ex}}\mathbf{∆}\mathbf{E}\mathbf{=}\mathbf{q}$

Problem Details

Suppose that the gas-phase reaction 2NO(g) + O2(g) → 2NO2(g) were carried out in a constant-volume container at constant temperature.

(a) Would the measured heat change represent ΔH or ΔE?

(b) If there is a difference, which quantity is larger for this reaction?