Question

What entropy change is associated with the reversible phase change from 1.0kg of ice to water at 0 ° C?

Answer 1

1200 J/K

Step-by-step explanation:

The formula for the entropy associated with a reversible phase change is

`\Delta S= \frac{q_{\text{rev}}}{T}`

1. Calculate q

For a reversible phase change like melting,

`q_{\text{rev}} = m\Delta_{\text{fus}}H = \text{1000 g} * \frac{\text{334 J}}{\text{1 g}} = \text{334 000 J}`

2. Calculate ΔS

`\Delta S = \frac{q_{\text{rev}}}{T} =\frac{\text{334 000 J}}{\text{273.15 K}} = \textbf{1200 J/K}`