As temperature increases, vapor pressure of a liquid generally:

As temperature increases, vapor pressure of a liquid generally:

• A. Be lower
• B. Be higher
• C. Remain the same
• D. Change chemical composition

Answer: (B)

Vapor pressure rises with temperature because heating gives more molecules enough kinetic energy to overcome the liquid’s intermolecular forces and escape into the vapor phase. The vapor pressure is the pressure exerted by those vapor molecules in equilibrium with the liquid; as more molecules evaporate, that pressure increases. This happens even though the liquid’s identity doesn’t change in normal conditions—the energy distribution shifts with temperature, increasing volatility. Statements that vapor pressure would be lower or stay the same contradict this energy-driven evaporation, and changing chemical composition would require a chemical reaction, not just heating.

Vapor pressure rises with temperature because heating gives more molecules enough kinetic energy to overcome the liquid’s intermolecular forces and escape into the vapor phase. The vapor pressure is the pressure exerted by those vapor molecules in equilibrium with the liquid; as more molecules evaporate, that pressure increases. This happens even though the liquid’s identity doesn’t change in normal conditions—the energy distribution shifts with temperature, increasing volatility. Statements that vapor pressure would be lower or stay the same contradict this energy-driven evaporation, and changing chemical composition would require a chemical reaction, not just heating.