1. 3.6Molar Concentration Molarity – A Useful Unit of Concentration Preparing a Standard Solution from a Solid Ions in Solution

2. Molarity – A Useful Unit of Concentration text pages 151-152 Concentration is any expression of the proportion of a chemical in a solution. Molarity (M) is the number of moles of the chemical per litre of solution, e.g. 1.8 M HCl means 1.8 mol HCl per litre of solution. The molar concentration of a chemical is indicated by putting square brackets around the chemical’s formula, e.g. [HCl]. 3.6Molar Concentration

3. text pages 151-152 Examples: 0.50 L soln x 3.0 mol HCl = 1.5 mol HCl 1 L soln 1.5 mol HCl x 1 L soln = 0.50 L soln 3.0 mol HCl 3.6Molar Concentration Molarity – A Useful Unit of Concentration

4. Preparing a Standard Solution from a Solid text pages 153-154 A standard solution is a solution of known concentration 3.6Molar Concentration

5. text pages 153-154 e.g. 0.25 L soln x 1.5 mol NaCl x 58.5 g NaCl = 22 g NaCl 1 L soln 1 mol NaCl 3.6Molar Concentration Preparing a Standard Solution from a Solid

6. text pages 155-157 Ions in Solution 3.6Molar Concentration The dissociation equation provides the ratio of the released ions to each other and to their parent compound. CaCl 2 (s) → Ca 2+ (aq) + 2Cl  (aq) 3.0 mol/L dissolves to form ?? 3.0 mol/L dissolves to form 3.0 M6.0 M

7. text pages 155-157 Ions in Solution e.g. 0.125 L soln x 1.5 mol CaCl 2 x 2 mol Cl  x 35.5 g Cl  = 13 g Cl  1 L soln 1 mol CaCl 2 1 mol Cl  Calcium chloride CaCl 2 moles grams litres of soln Formula units ions Chloride Cl Chloride Cl  3.6Molar Concentration litres litres of soln litres