The steam reforming of methane is a key industrial process used to produce hydrogen gas. The reaction is represented by the equation:
CH4(g)+H2O(g)⟶CO(g)+3H2(g)ΔH⊖=+206 kJ mol−1 \text{CH}_4(\text{g}) + \text{H}_2\text{O}(\text{g}) \longrightarrow \text{CO}(\text{g}) + 3\text{H}_2(\text{g}) \quad \Delta H^{\ominus} = +206 \text{ kJ mol}^{-1} CH4(g)+H2O(g)⟶CO(g)+3H2(g)ΔH⊖=+206 kJ mol−1Some standard entropy data are shown in the table below:
| Substance | CH4(g)\text{CH}_4(\text{g})CH4(g) | H2O(g)\text{H}_2\text{O}(\text{g})H2O(g) | CO(g)\text{CO}(\text{g})CO(g) | H2(g)\text{H}_2(\text{g})H2(g) |
|---|---|---|---|---|
| S⊖ / J K−1mol−1S^{\ominus} \text{ / J K}^{-1} \text{mol}^{-1}S⊖ / J K−1mol−1 | 186.3186.3186.3 | 188.8188.8188.8 | 197.6197.6197.6 | 130.7130.7130.7 |
Use the equation and the entropy data to calculate the Gibbs free-energy change (ΔG\Delta GΔG) for this reaction at 800 ∘C800\,^{\circ}\text{C}800∘C. Give your answer to the appropriate number of significant figures.
Use your answer to explain whether this reaction is feasible.
