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The enthalpy of vaporization of a certai...

The enthalpy of vaporization of a certain liquid at its boiling point of `35^(@)C` is `24.64 kJ "mol"^(-1)`.The value of change in entropy for the process is

A

`704 J K^(-1) "mol"^(-1)`

B

`80 J K^(-1) "mol"^(-1)`

C

`24.64 J K^(-1) "mol"^(-1)`

D

`7.04 J K^(-1) "mol"^(-1)`

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The correct Answer is:
To find the change in entropy (ΔS) for the vaporization process of the liquid at its boiling point, we can follow these steps: ### Step 1: Understand the relationship between ΔG, ΔH, and ΔS At equilibrium (which is the case at the boiling point), the change in Gibbs free energy (ΔG) is zero. According to the Gibbs-Helmholtz equation: \[ ΔG = ΔH - TΔS \] Since ΔG = 0, we can rearrange the equation: \[ ΔH = TΔS \] ### Step 2: Rearranging to find ΔS From the rearranged equation, we can express ΔS as: \[ ΔS = \frac{ΔH}{T} \] ### Step 3: Convert the enthalpy of vaporization to Joules The enthalpy of vaporization is given as 24.64 kJ/mol. To convert this to Joules: \[ ΔH = 24.64 \, \text{kJ/mol} \times 1000 \, \text{J/kJ} = 24640 \, \text{J/mol} \] ### Step 4: Convert the temperature to Kelvin The boiling point of the liquid is given as 35°C. To convert this to Kelvin: \[ T = 35 + 273 = 308 \, \text{K} \] ### Step 5: Calculate ΔS Now, we can substitute the values of ΔH and T into the equation for ΔS: \[ ΔS = \frac{24640 \, \text{J/mol}}{308 \, \text{K}} \] ### Step 6: Perform the calculation Calculating the above expression: \[ ΔS = \frac{24640}{308} \approx 80 \, \text{J/K/mol} \] ### Final Answer Thus, the change in entropy (ΔS) for the vaporization process is approximately: \[ ΔS \approx 80 \, \text{J/K/mol} \]

To find the change in entropy (ΔS) for the vaporization process of the liquid at its boiling point, we can follow these steps: ### Step 1: Understand the relationship between ΔG, ΔH, and ΔS At equilibrium (which is the case at the boiling point), the change in Gibbs free energy (ΔG) is zero. According to the Gibbs-Helmholtz equation: \[ ΔG = ΔH - TΔS \] Since ΔG = 0, we can rearrange the equation: \[ ΔH = TΔS \] ...
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