CHEM 102 Lecture Notes - Lecture 12: Freezing-Point Depression, Boiling-Point Elevation, Ethylene Glycol
Document Summary
Chem 102: general descriptive chemistry ii - lecture 12: more colligative. 50. 0 ml of glycerin into 500 ml of water at 25 degrees celsius. Glycerin has density of 1. 26 g/ml at 25 degrees celsius. The normal vapor pressure of solution at 25 degrees celsius is 23. 8 torr. Boiling point elevation: formula, tb = kb x m, tb = change in boiling point. To determine the new boiling point, you must add this value to the original boiling point: kb = molal boiling point elevation constant, m = molality. Example problem: a solution of ethylene glycol (c2h6o2) is 25% by mass in water. The kb for the solvent is 0. 51 degrees c/m. Freezing point depression: tf = kf x m, tf = change in normal freezing point the original freezing point, kf = molal freezing point depression constant, m = molality.
