The Sidney Young equation is used to correct values of this quantity based on changes in pressure. Various values of this quantity form the two axes of a Dühring plot. Mole fractions for the substance with a smaller value of this quantity define the axes of a McCabe–Thiele plot. By reducing pressure, a rotovap lowers the value of this quantity (-5[1])for the solvent in the flask. (-5[1])Negative (10[1])azeotropes have a higher value of this (10[1])quantity (10[1])than either of their components, and hence cannot be separated by simple distillation. (10[1])The ebullioscopic constant times molality (-5[1])times van (10[1])’t Hoff factor calculates a colligative property known as this quantity’s namesake “elevation.” For 10 points, name this quantity of a substance at which vapor pressure (10[1])equals surrounding pressure, causing it to vaporize. (10[1])■END■ (10[2])