1. SOLUTIONS 1.Concentration Units A.Molarity; mole fraction; % m/m; molality 2.Principles of Solubility A. solute-solvent interactions; effect of T & P; 3.Colligative Properties A.VP lowering; BP elevation; FP depression; osmotic pressure B.Molar mass determination from colligative prop 4.Colligative Properties of Electrolytes

2. 0. Review: solution = homogeneous mixture of solute and solvent. solute = substance being dissolved solvent = substance doing the dissolving Solutions exist as gases, liquids, or solids Air = 78% N 2, 21% O 2, others (e.g., Ar 0.1%) nickel coin = 25% Ni, 75% Cu

5. Concentration Units (con’t) Conversions Between Concentration Units When the Original [] IsStart With Molarity (M) Start with 1.00 L solution

6. Concentration Units (con’t) Conversions Between Concentration Units When the Original [] IsStart With Mole Fraction (X A ) Start with 1 mol (solute + solvent)

7. Concentration Units (con’t) Conversions Between Concentration Units When the Original [] IsStart With Mass Percent, % (m/m) Start with 100 g solution % = *100; parts per thousand = *1000; ppm = * 10 6 ; etc.

8. Concentration Units (con’t) Conversions Between Concentration Units When the Original [] IsStart With molality (m) Start with 1000 g solvent

9. Example – Concentrated HCl The amount of HCl in concentrated solution = 37.7% A. What are %’s of HCl & water in concentrated HCl? HCl = 37.7% H 2 O = 100.0 – 37.7 = 62.3%