Solution Stoichiometry Topic 8.3

Expressing Concentration a solution can be described as concentrated or dilute. concentration is a ratio of the quantity of solute to the quantity of solution most calculations that involve solutions require quantitative of concentration. thus a solution with a concentration of 50 g per litre of solution is more dilute than a solution with 52 g of the same solute per litre of solution

Calculating Percent Concentrations There are three common methods for expressing percent concentration: mass/volume percent, or percent (m/v) mass percent, or percent (m/m) volume percent, or percent (v/v)

Mass/Volume Percent Expresses the mass of solute dissolved in a volume of solution as a percent: Percent(m/v) = mass of solute [in grams] X 100% mass of solution [in millilitres] Read pgs of text (MHR chemistry 11) and look at worked examples and practice problems

Mass Percent Expressed as a percent ratio of the mass of the solute to the mass of the solution: Percent(m/m) = mass of solute X 100% mass of solution Read pgs of text (MHR chemistry 11) and look at worked examples and practice problems

Very Small Concentrations Expressed in terms of parts per million or parts per billion: Both are fractions with the mass of solute divided by mass of the solution ppm = mass of solute ppb= mass of solute Read pgs of text (MHR chemistry 11) and look at worked examples and practice problems mass of solution X 10 6 mass of solution X 10 9

Solutions Concentration is expressed in terms of the mass or amount of solute dissolved in 1 dm 3 of solution g/dm 3 or mol/dm 3

Molarity is a term used to express concentration. The units of molarity are moles per liter (It is abbreviated as a capital M) = mol/dm 3 gram/dm 3 or g/dm 3

Practice Problems