Question

The enthalpy of fusion of water is $1.435\, kcal/mol.$ The molar entropy change for the melting of ice at $0^{\circ}C$ is :

• A. 5.260cal /(molK)
• B. 0.526cal /(molK)
• C. 10.52 cal /(molK)
• D. 21.04 cal /(molK)

Answer 1

The Correct Option is A

 The question requires us to find the molar entropy change for the melting of ice at \({0^\circ C}\). The enthalpy of fusion (ΔH) is given as \(1.435 \, \text{kcal/mol}\).

Entropy change (ΔS) for a phase change can be calculated using the formula:

\(\Delta S = \frac{\Delta H}{T}\)

1. First, convert the enthalpy of fusion from kilocalories to calories:
2. Next, find the temperature in Kelvin, since the enthalpy and entropy changes are typically computed at absolute temperatures:
3. Now calculate the entropy change:

Therefore, the molar entropy change for the melting of ice at \({0^\circ C}\) is approximately \(5.260 \, \text{cal/(mol K)}\), which is the correct answer.

Hence, the correct option is 5.260 cal/(mol K).