1. Solutions & Chemical Equilibrium
Section 2: Concentration
Concentration
Molarity
Calculations
mol L
M =

2. A. Concentration Concentration
the amount of solute dissolved in a given amount of solvent
Dilute – less solute
Concentrated – more solute

3. B. Molarity Molarity (M) moles of solute per liter of solution
Example:
3 M HCl molar HCl mol HCl
1 L

4. B. Molarity Preparing a Solution
(in lab later)
To make a 0.5 M (0.5 molar) solution, first add 0.5 mol of solute to a 1 L volumetric flask half filled with distilled water.

5. B. Molarity Preparing a Solution
(in lab later)
Swirl the flask carefully to dissolve the solute.

6. B. Molarity Preparing a Solution
(in lab later)
Fill the flask with water exactly to the 1 L mark.

7. C. Calculations Finding Molarity
What is the molarity of a solution containing g NaCl in 100 mL of solution?
1 mol NaCl
58.44 g NaCl
0.900 g NaCl x =
mol NaCl
IV saline solution
mol NaCl L
0.150 M NaCl =
100 mL = L

8. C. Calculations Finding Molarity
What is the molarity of a solution with a volume of 2.00 L containing 36.0 g of C6H12O6 (glucose)?
1 mol C6H12O6
g C6H12O6
36.0 g C6H12O6 x =
0.200 mol C6H12O6
0.200 mol C6H12O L =
0.100 M C6H12O6

9. C. Calculations Finding Moles
How many moles of solute are in 3.80 L of M NaClO (bleach)?
0.700 mol NaClO
1 L
3.80 L x =
2.66 mol NaClO
0.700 M written as mol/L
bleach

10. C. Calculations Finding Moles
How many moles of solute are in 250 mL of M CaCl2?
0.250 L x mol CaCl2 =
1 L
0.550 mol CaCl2
250 mL = L

11. C. Calculations Finding Mass (g)
What mass of sodium hydroxide (NaOH) is needed to make 200 mL of a M solution?
0.200 L x mol NaOH =
1 L
mol NaOH x g NaOH =
1 mol
mol NaOH
bleach
1.20 g NaOH

12. C. Calculations Finding Volume (L)
How many liters of a 1.15 M solution are needed to give moles of solute?
0.805 mol x L =
1.15 mol
How many mL are needed?
0.700 L
bleach
0.700 L = 700 mL