1. What are we doing Today?
Review Day
Homework Questions
Review
In class questions & homework

2. HW Check
1) P  Numbers 21-25

3. Magnetic Field Direction
The north pole of a compass points in the direction of the magnetic field.
This direction is always away from a north magnetic pole and toward a south magnetic pole.

5. Solubility & Concentration

6. Concentration of Solution
Solvent Solute

7. Concentration of Solution
Molarity
Parts ratio
% m/V , m/m , V/V
Moles of solute
Liter of solution
Mol L
(C) = =
amount of solute (g or ml)
amount of solution (g or ml) =
(102) or (106) or (109)

8. Molarity Example Problem 1
NaCl
12.6 g of NaCl are dissolved in water making 344mL of solution. Calculate the molar concentration.
C = n / V
C = concentration
n = solute (mol)
V = Volume (L)

9. Molarity Example Problem 2
NaCl
How many moles of NaCl are contained in 250.mL of solution with a concentration of 1.25 M?
C = n / V
Volume x concentration = moles solute

10. Molarity Example Problem 3
NaCl
What volume of solution will contain 15 g of NaCl if the solution concentration is 0.75 M?
C = n / V
moles solute ÷ concentration = volume solution

11. Mass and volume units must match.
% Concentration
% (w/w) =
% (w/v) =
% (v/v) =
Mass and volume units must match.
(g & mL) or (Kg & L)

12. % Concentration Example Problem 1 Example Problem 2
(Solid in a Liquid)
What is the concentration in %w/v of a solution containing 39.2 g of potassium nitrate in 177 mL of solution?
% (w/v) =
Example Problem 2
(Liquid in a Liquid)
What is the concentration in %v/v of a solution containing 3.2 L of ethanol in 6.5 L of solution?
% (v/v) =

13. What volume of 1.85 %w/v solution is needed to
% Concentration
Example Problem 3
What volume of 1.85 %w/v solution is needed to
provide 5.7 g of solute?
% (w/v) =
We know:
We want to get:
g solute ÷ concentration = volume solution

14. Parts per million/billion (ppm & ppb)or
= ppm or
= ppb
AND
For very low concentrations:
= ppt
parts per trillion
Mass and volume units must match.
(g & mL) or (Kg & L)

15. ppm & ppb or Example Problem 1
An Olympic sized swimming pool contains 2,500,000 L of water. If 1 tsp of salt (NaCl) is dissolved in the pool, what is the concentration in ppm?
1 teaspoon = 6.75 g NaCl or

16. ppm & ppb or Example Problem 2
An Olympic sized swimming pool contains 2,500,000 L of water. If 1 tsp of salt (NaCl) is dissolved in the pool, what is the concentration in ppb?
1 teaspoon = 6.75 g NaCl or