boiling point The temperature at which the liquid and gas phases of a substance are in equilibrium at a specified pressure; the temperature at which the vapor pressure of a liquid becomes equal to the external pressure. The boiling point increases as the external pressure increases and falls as it decreases. It is usually measured at a standard pressure of one atmosphere (760mm of mercury, 101.325 kPa). The boiling point of pure water at standard pressure is 100°C (212°F). Measurement of boiling point is important in chemical analysis and the determination of relative molecular masses. Compare with melting point. Related categories • HEAT AND THERMODYNAMICS PROPERTIES OF MATTER Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) |