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 for the solvent in the flask. Negative azeotropes have a higher value (10[1])of this quantity (10[1])than either of their components, (10[1])and hence cannot be separated (10[1])by simple distillation. (10[3])The ebullioscopic constant times molality times van ’t Hoff factor calculates a colligative property known as this quantity’s namesake “elevation.” (10[1])For 10 points, name this quantity of a substance at which vapor pressure equals surrounding pressure, causing it to vaporize. ■END■