Using this graph of CS2 data, determine (a) the approximate vapor pressure of CS2 at 30°C,

Key Concepts

Vapor Pressure

Vapor pressure is the pressure exerted by a vapor in equilibrium with its liquid or solid phase at a given temperature. It reflects the tendency of particles to escape from the liquid phase into the vapor phase. Higher temperatures generally increase vapor pressure, as more molecules have sufficient energy to overcome intermolecular forces.

Phase Equilibrium

Phase equilibrium occurs when the rates of the forward and reverse processes of a phase change are equal, resulting in no net change in the amount of each phase. In the context of vapor pressure, this means that the number of molecules evaporating from the liquid equals the number condensing back into it, allowing for a stable vapor pressure at a specific temperature.

Temperature Dependence of Vapor Pressure

The vapor pressure of a substance is highly dependent on temperature, typically increasing as temperature rises. This relationship is often described by the Clausius-Clapeyron equation, which relates the change in vapor pressure with temperature to the enthalpy of vaporization. Understanding this concept is crucial for interpreting vapor pressure data at different temperatures.