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Ch.18 - Free Energy and Thermodynamics
Chapter 18, Problem 78

Estimate the value of the equilibrium constant at 655 K for each reaction in Problem 74. (ΔHf° for BrCl is 14.6 kJ/mol.)

Verified step by step guidance
1
Identify the reaction for which you need to estimate the equilibrium constant. Since the problem refers to Problem 74, ensure you have the correct chemical equation.
Use the van 't Hoff equation to relate the change in the equilibrium constant with temperature: \( \ln \left( \frac{K_2}{K_1} \right) = -\frac{\Delta H^\circ}{R} \left( \frac{1}{T_2} - \frac{1}{T_1} \right) \).
Determine the values needed for the van 't Hoff equation: \( \Delta H^\circ = 14.6 \text{ kJ/mol} \) (convert to J/mol), \( R = 8.314 \text{ J/mol K} \), and the temperatures \( T_1 \) and \( T_2 \) in Kelvin.
Assume or find the initial equilibrium constant \( K_1 \) at a known temperature \( T_1 \). If not given, you may need to use standard conditions or additional data from Problem 74.
Solve the van 't Hoff equation for \( K_2 \), the equilibrium constant at 655 K, using the values obtained in the previous steps.