The value of P is — Chemical Equilibrium Chemistry Question

💡 Solution & Explanation

Let 'p' be the pressure exerted by H₂S formed at equilibrium. Since 1 mole of H₂S is formed with 1 mole of NH₃ from the dissociation, the pressure of NH₃ increases by 'p'. At equilibrium, P_NH₃ = P + p = 625 mm. Total pressure P_total = P_NH₃ + P_H₂S = (P + p) + p = 625 + p = 725 mm. Therefore, p = 725 - 625 = 100 mm. Substituting 'p' back into the equation for NH₃: P + 100 = 625, so P = 525 mm. Therefore, correct answer is C.