1. Ch. 3 & 7 – The Mole
II. Concentration (p )

2. II. Concentration
Measures the relative amounts of the two substances making up a solution.
solute: the substance being dissolved
solvent: the liquid doing the dissolving
solution: the combination of the two

3. substance being dissolved
A. Molarity
1. Concentration of a solution.
substance being dissolved
total combined volume

4. A. Molarity
2M HCl
1. What does this mean?

5. 2. Molarity Calculations
6.02  1023
(particles/mol)
molar mass
(g/mol)
MASS IN
GRAMS
MOLES
NUMBER OF
PARTICLES
LITERS
SOLUTION
Molarity
(mol/L)

6. 2. Molarity Calculations
How many grams of NaCl are required to make 0.500L of 0.25M NaCl?
0.500 L
0.25 mol
1 L
58.44 g
1 mol
= 7.3 g NaCl

7. 2. Molarity Calculations
Find the molarity of a 250 mL solution containing 10.0 g of NaF.
10.0 g
1 mol
41.99 g
= mol NaF
0.238 mol
0.25 L
M =
= 0.95M NaF

8. substance being dissolved
A. Molality
1. Concentration of a solution.
substance being dissolved
Mass of solvent

9. A. Molality
2m HCl
1. What does this mean?

10. 2. Molality Calculations
6.02  1023
(particles/mol)
molar mass
(g/mol)
MASS IN
GRAMS
MOLES
NUMBER OF
PARTICLES kg
SOLVENT
Molality
(mol/kg)

11. 2. Molality Calculations
How many grams of NaCl are required to make 0.50m NaCl with 1.50kg of H2O?
1.50kg
0.50 mol
1.00 kg
58.44 g
1 mol
= 44 g NaCl

12. 2. Molality Calculations
Find the molality of solution containing 10.0 g of NaF and kg H2O.
10.0 g
1 mol
41.99 g
= mol NaF
0.238 mol kg
m =
= 4.76 m NaF