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The K(a) for CH(3)COOH at 300 and 310 K ...

The `K_(a)` for `CH_(3)COOH` at `300` and `310 K` are `1.8 xx 10^(-5)` and `1.805 xx 10^(-5)`, respectively. The enthalpy of deprotonation for acetic acid is `51.6 cal`.

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To solve the problem, we will use the Van't Hoff equation, which relates the change in the equilibrium constant (K) with temperature and the enthalpy change (ΔH) of the reaction. ### Step-by-Step Solution: 1. **Identify the Given Values:** - \( K_a \) at \( 300 \, K \) (T1) = \( 1.8 \times 10^{-5} \) - \( K_a \) at \( 310 \, K \) (T2) = \( 1.805 \times 10^{-5} \) - Enthalpy of deprotonation (ΔH) = \( 51.6 \, \text{cal} \) - Universal gas constant (R) = \( 1.987 \, \text{cal/(mol·K)} \) 2. **Write the Van't Hoff Equation:** \[ \ln \left( \frac{K_2}{K_1} \right) = -\frac{\Delta H}{R} \left( \frac{1}{T_2} - \frac{1}{T_1} \right) \] Here, \( K_1 = K_a \) at \( T_1 \) and \( K_2 = K_a \) at \( T_2 \). 3. **Substitute the Known Values:** \[ \ln \left( \frac{1.805 \times 10^{-5}}{1.8 \times 10^{-5}} \right) = -\frac{\Delta H}{1.987} \left( \frac{1}{310} - \frac{1}{300} \right) \] 4. **Calculate the Left Side:** - First, calculate the fraction: \[ \frac{1.805 \times 10^{-5}}{1.8 \times 10^{-5}} \approx 1.00278 \] - Now, take the natural logarithm: \[ \ln(1.00278) \approx 0.00277 \] 5. **Calculate the Right Side:** - Calculate \( \frac{1}{310} - \frac{1}{300} \): \[ \frac{1}{310} \approx 0.0032258, \quad \frac{1}{300} \approx 0.0033333 \] \[ \frac{1}{310} - \frac{1}{300} \approx -0.0001075 \] - Substitute back into the equation: \[ 0.00277 = -\frac{\Delta H}{1.987} \times (-0.0001075) \] 6. **Rearrange to Solve for ΔH:** \[ \Delta H = \frac{0.00277 \times 1.987}{0.0001075} \] - Calculate: \[ \Delta H \approx \frac{0.0055}{0.0001075} \approx 51.2 \, \text{cal} \] 7. **Conclusion:** - The calculated ΔH (approximately \( 51.2 \, \text{cal} \)) is not equal to the given ΔH (51.6 cal). Therefore, the statement regarding the enthalpy of deprotonation is **false**.

To solve the problem, we will use the Van't Hoff equation, which relates the change in the equilibrium constant (K) with temperature and the enthalpy change (ΔH) of the reaction. ### Step-by-Step Solution: 1. **Identify the Given Values:** - \( K_a \) at \( 300 \, K \) (T1) = \( 1.8 \times 10^{-5} \) - \( K_a \) at \( 310 \, K \) (T2) = \( 1.805 \times 10^{-5} \) - Enthalpy of deprotonation (ΔH) = \( 51.6 \, \text{cal} \) ...
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