H O l H O vap. Point out the correct statement for this equilibrium — Chemical Equilibrium Chemistry Question

💡 Solution & Explanation

# Analysis of H₂O(l) ⇌ H₂O(vap) Equilibrium Without seeing the options, I'll cover the key correct statements for this liquid-vapor equilibrium: ## Key Principles: **1) Equilibrium Constant is Temperature-Dependent** $$K_p = P_{vap} \text{ (at a given temperature)}$$ The vapor pressure changes only with temperature, not with the amounts of liquid or vapor present. **2) Nature of the System at Equilibrium** - Rate of evaporation = Rate of condensation - This is a **dynamic equilibrium** — molecular exchange occurs continuously - The number of molecules in each phase remains constant **3) Effect of Added Variables** | Variable | Effect | |----------|--------| | Adding more liquid | No change to $P_{vap}$ or equilibrium | | Increasing temperature | $P_{vap}$ increases; equilibrium shifts right | | Decreasing pressure | Liquid evaporates until $P_{vap}$ is restored | | Container size (with liquid present) | No effect on $P_{vap}$ | **4) Thermodynamic Properties** - $\Delta G = 0$ at equilibrium - At $T < T_{bp}$: $\Delta G > 0$ (liquid favored) - At $T = T_{bp}$: $\Delta G = 0$ (coexistence) - At $T > T_{bp}$: $\Delta G < 0$ (vapor favored) --- **The correct answer typically emphasizes:** The vapor pressure is independent of liquid/vapor amounts and depends only on temperature, or that it's a dynamic equilibrium where both phases coexist at constant composition.