1. Solution Concentration

2. Introduction
Cyanide is a very lethal poison. In the form of a pill has been used to kill people.
However, cyanide is also present in apples.
Why don’t we die when we eat an apple? Exception: Snow White
Different concentrations have different effects on the human body.
Dose makes the poison!

3. Concentration …is the amount of solute per quantity of solvent
There are several ways that chemists express the concentration of solutions.

4. Mass/Volume percent (m/v%)
Example:
What mass of CuSO4(s) is required to make 2.5 L of 3.8% (m/v) CuSO4(aq)?
Let x represent the unknown and solve using ratios.
(ans: 95 g)
95 g of CuSO4(s) should be used to make 2.5 L of solution

5. Mass/Mass percent (m/m%)
Example: 2. Sterling silver has a percent (m/m) composition of 92.5% Ag and 7.5% Cu. What mass of copper is required to make 5.8 kg of sterling silver? Let x represent the unknown and solve using ratios. (ans: 4.4 x 102 g)

6. Volume/Volume percent (v/v%)
Example: 3. What volume of pure alcohol is present in a 750 mL bottle of 12.5% (v/v) wine? Let x represent the unknown and solve using ratios. (ans: 94 mL)

7. Solution Concentration

8. Parts per Million (ppm)
Very Small Concentrations
Parts per Million (ppm)
Parts per Billion (ppb)

9. Very Small Concentrations
Example: 4. If the acceptable limit of lead in water is 0.25 ppb, what mass of water must you consume (drink) to be the equivalent of 1.0 g of lead? (ans: 4.0x109 g)

10. Solutions
Molar Concentration

11. Molar Concentration (Molarity) - Using Moles!
Molar concentration is the number of moles of solute that is dissolved in one litre of solution.
Units: (mol/L)

12. Molar Concentration Examples
5. A CuSO4(aq) solution contains 0.55 g of CuSO4(s) in 85 mL of solution.
What is the molar concentration of this solution?
(ans: mol/L)
6. What mass of NaCl(s) can be recovered by evaporating 150 mL of 0.35 mol/L NaCl(aq)?
(ans: 3.1 g)