What is the change in entropy when 0.517 g of water decomposes to form hydrogen gas and oxygen gas at 298 K?
2H₂O(l) → 2H₂(g) + O₂(g) ; ΔS° = 326.3 J/K at 298 K

Question

Quizplus · Accepted Answer

The given change in entropy (ΔS°) is 326.3 J/K for the decomposition of water into hydrogen gas and oxygen gas. This value is per mole of reaction. The molar mass of water (H2O) is approximately 18.015 g/mol. Given that 0.517 g of water is decomposing, we first find the number of moles of water: $0.517 \, \text{g} \times \frac{1 \, \text{mol}}{18.015 \, \text{g}} = 0.0287 \, \text{mol}$. Then, we multiply the moles of water by the given ΔS° to find the change in entropy for the given amount of water: $0.0287 \, \text{mol} \times 326.3 \, \text{J/K/mol} = 9.36 \, \text{J/K}$.

What Is the Change in Entropy When 0