I. Solutions - review

A. Definitions
1. solute
2. solvent
3. general descriptors: dilute, concentrated, saturated, supersaturated.
 
B. Examples :

 C. Expression of composition of solution
1. Molarity (M): moles solute/liter sol'n
2. Molality (molal): moles solute/Kg solvent
3. Weight percent (wt. %):
    (grams solute/grams solution)100
4. Mole fraction (X):
    number of moles of solute/total moles sol'n
5. Normality (N): moles equivalents/liter sol'n
6. Calculation example:
        create a dilute solution (0.50 M) of sulfuric acid from concentrated (18 M) stock.
            a. McVc = MdVd (18)(x) = (0.50)(100 mL); x = 2.78 mL
            b. measured out 3.0 mL:
                (3.0 mL/1000 mL/L)(18 M)?0.100 L = 0.54 M
            c. Molality?:
                (.054 moles H2SO4 in (100-3) mL of H2O (or 0.097 Kg): 0.5567 molal = 0.56.
            d. wt. %?: density of 18M H2SO4: 1.84 g/mL
                (0.054 mol H2SO4) 98.074 g/mol = 5.30g H2SO4
                (3.0 mL)(1.84 g/mL) = 5.52g; 5.52-5.30 = 0.22g H2O
                (5.30/97+5.52)100 = 5.17 wt. % = 5.2 wt. %
            e. Mole fraction of acid?:
                97.22g?18 g/mole = 5.40 moles H2O
                (0.054 mol)?(0.054+5.40 mol) = 0.009899 = 0.0099
            f. Normality?: 2 equivalents/mole H2SO4
                (0.54 M)2 = 1.08 N = 1.1 N.