ΔH° for the cell reaction per mol of AgCl is — Electrochemistry Chemistry Question

💡 Solution & Explanation

For 1 mole of AgCl, n = 1. Temperature coefficient ∂E/∂T = (0.21 - 0.23) / (35 - 15) = -0.001 V/K. At 25°C (298 K), the interpolated cell potential E = 0.22 V. ΔG = -nFE = -1 × 96500 × 0.22 = -21230 J. ΔS = nF(∂E/∂T) = 1 × 96500 × (-0.001) = -96.5 J/K. Enthalpy change ΔH = ΔG + TΔS = -21230 + 298(-96.5) = -21230 - 28757 = -49987 J. Therefore, correct answer is B.