The temperature at which liquid and vapour are at equilibrium at one atmosphere is the normal:

1. Liquid and vapour coexist when a liquid boils. 2. That temperature is quoted at a standard pressure. 3. The temperature at which liquid and vapours are at equilibrium is the normal boiling point of the liquid. 4. So the answer is the boiling point. _Source: NCERT Class XI Chemistry Part I, Unit 6 'Equilibrium'_