The Clausius-Clapeyron equation relates vapor pressure to temperature. In this context, which quantity changes with temperature?

The Clausius-Clapeyron equation relates vapor pressure to temperature. In this context, which quantity changes with temperature?

• A. Vapor-liquid equilibrium
• B. Vapor pressure and temperature
• C. Daltons law
• D. Ideal gas law

Answer: (B)

The Clausius-Clapeyron equation shows how the equilibrium vapor pressure of a liquid changes when temperature is varied. In this relationship, vapor pressure is the quantity that changes as temperature changes, with temperature acting as the driving variable. The equation expresses vapor pressure as a function of temperature (for example, d(ln P)/dT = ΔHvap/(R T^2) or P ≈ P0 exp(-ΔHvap/(R T))), so increasing temperature leads to higher vapor pressure. This is why the option that ties vapor pressure to temperature is the best answer: the two quantities linked by the relation are vapor pressure and temperature. The other choices describe broader concepts or laws that don’t capture this specific dependence of vapor pressure on temperature in a phase equilibrium.

The Clausius-Clapeyron equation shows how the equilibrium vapor pressure of a liquid changes when temperature is varied. In this relationship, vapor pressure is the quantity that changes as temperature changes, with temperature acting as the driving variable. The equation expresses vapor pressure as a function of temperature (for example, d(ln P)/dT = ΔHvap/(R T^2) or P ≈ P0 exp(-ΔHvap/(R T))), so increasing temperature leads to higher vapor pressure. This is why the option that ties vapor pressure to temperature is the best answer: the two quantities linked by the relation are vapor pressure and temperature. The other choices describe broader concepts or laws that don’t capture this specific dependence of vapor pressure on temperature in a phase equilibrium.