Solution Concentration

Dilute Solutions Small quantity of solute per unit volume of solution. Concentrated Solutions Large quantity of solute per unit volume of solution.

Concentration The concentration of a solution is the quantity of solute in a solution. C = quantity of solute quantity of solution Can be described as: –v/v % (when solute is a liquid) –m/v % (when solute is a solid) –m/m % (when both solute & solvent are solids)

Everyday Examples Vinegar is 5% v/v acetic acid –5 mL of CH 3 COOH in 100 mL vinegar Hydrogen peroxide is 3% m/v –3 g of H 2 O 2 per 100 mL of solution Yogurt is 2% m/m –2 g of milk fat per 100 g yogurt

E.g what is the molarity of a 250 mL solution that contains 2.00 g of NaOH? Concentrations in Chemistry Molar concentration (molarity) –Moles of solute dissolved in one liter of solution –Units: mol/L (or lazy chemists sometimes use M) n = 2.00 g X 1 mol g = mol C = mol L = mol/L MM = g/mol m = 2.00 g V = L n = ? C = ?

Concentrations in Chemistry Parts per million or Parts per billion –“polution solutions” –Very low concentrations –ppm = 1 drop in a bath tub –ppb = 1 drop in a swimming pool –ppt = 1 drop in a 1000 swimming pools

Practice Worksheet P. 284 #1-8,10 P. 287 #11-17 P. 290 #19-22 P. 290 #1-7,9,10