Final answer:
The vapor pressure of a liquid increases as temperature rises due to the greater average kinetic energy of the molecules, which enables more of them to escape into the gas phase and increase the vapor pressure.
Step-by-step explanation:
The vapor pressure of a liquid increases with temperature because the average kinetic energy (KE) of its molecules also increases. When the temperature of a liquid rises, molecules gain more energy and move faster. This results in a higher number of molecules having sufficient kinetic energy to overcome intermolecular forces and escape from the liquid surface into the gas phase, thereby raising the vapor pressure.
The relationship between vapor pressure and temperature is not linear; it increases exponentially because the fraction of molecules with enough energy to vaporize increases significantly with temperature. Therefore, as the temperature increases, more molecules enter the gas phase, and vapor pressure rises accordingly. This process continues until dynamic equilibrium is achieved, where the rate of evaporation equals the rate of condensation, and the vapor pressure remains constant at a given temperature.