The temperature and vapor pressure of a substance are related by the Clausius-Clapeyron equation, which states that:
ln(P2/P1) = -(ΔHvap/R) x (1/T2 - 1/T1)
where P1 and P2 are the vapor pressures of the substance at temperatures T1 and T2, respectively, ΔHvap is the enthalpy of vaporization at the boiling temperature, R is the gas constant, and ln represents the natural logarithm.
This equation shows that as the temperature of the substance increases, its vapor pressure also increases, assuming the enthalpy of vaporization remains constant. Conversely, as the temperature decreases, the vapor pressure decreases.