The boiling point of a liquid is the temperature at which its vapor pressure equals:

1. Boiling is defined by a pressure match, not a fixed temperature. 2. The boiling point of a liquid is a temperature defined by its vapor pressure. 3. It is the temperature at which vapor pressure equals ambient atmospheric pressure. 4. Adding solute lowers vapor pressure, so the boiling point rises. _Source: OpenStax Chemistry 2e (CC BY 4.0), Ch 11 'Solutions and Colloids', sections 11.1-11.5_