30.4 kJ is required to melt one mole of sodium chloride. The entropy change during melting is 28.4 JK-1 mol-1 . atm The melting point of sodium chloride Calculate is ___ K(Nearest Integer).
Show Hint
The melting point of a substance can be calculated by dividing the enthalpy change by the entropy change during melting.
Correct Answer: 1070
Solution and Explanation
Melting Point Calculation
The relationship between enthalpy (ΔH) and entropy (ΔS) during a phase change is:
ΔS = ΔH / T
Rearranging to find the melting point (Tmp):
Tmp = ΔH / ΔS
Substituting the given values:
- ΔH = 30.4 kJ mol-1 = 30400 J mol-1
- ΔS = 28.4 J K-1 mol-1
Tmp = 30400 / 28.4 = 1070.42 K
The nearest integer value is 1070 K.
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