1. Diluting Solutions
Lesson 6

2. Concentrated solutions have a relatively high molarity.
Diluting Solutions
Concentrated solutions have a relatively high molarity.
Dilute solutions have a relatively low molarity.
It is often faster to prepare a number of standard solutions by diluting a more concentrated solution.
The following equation can be used to solve dilution problems – when water is added or removed from a solution.
M1V1 = M2V2
M1= the initial molarity M2 = the final molarity
V1 = the initial volume V2 = the final volume

3. Initial Solution
mL of 0.10 M solution is diluted by adding 75.0 mL of water. Calculate the molarity of the new solution.
25.0 mL mL
M1 = M
M2 = ?
V2 = mL
V1 = mL
M1V = M2V2
(0.10 M)(25.0 mL) = M2(100.0 mL)
M = M

4. Initial Solution
What volume of M CoCl2 solution can be diluted to mL in order to make a M solution?
M1V1 = M2V2
(0.250 M) V = ( M)(100.0 mL)
V = mL

5. 3. 50. 0 mL of 0. 500 M CuSO4 solution is diluted to 250. 0 mL
mL of M CuSO4 solution is diluted to mL. Calculate the new concentration and the number of grams CuSO4 in the new solution.
M1 V = M2V2
(0.500 M) (50.0 mL) = M2 (250.0 mL)
M2 = M L
x mol
x g
= g
1 L
1 mol

6. 4. 1. 53 g of NaCl is dissolved in 100. 0 mL of water
g of NaCl is dissolved in mL of water. Calculate the molarity. The solution is concentrated by evaporating off 60.0 mL of water. Calculate the new molarity.
1.53 g
58.5 g
1 mol x
[ NaCl ] = =
0.262 M L
M1V1 = M2V2
100.0 mL – 60.0 mL
( M)(100.0 mL) = M2(40.0 mL)
M2 = M

7. 5. What volume of 0. 200 M CuSO4 solution must be diluted to 500
5. What volume of M CuSO4 solution must be diluted to mL to produce a M solution?
M1V1 = M2V2
(0.200 M)(V1) = (0.150 M)(500.0 mL)
V1 = mL

8. Initial Solution
6. What volume of water must be added to mL of M NaCl solution to change its concentration to M?
M1V1 = M2V2
(0.200 M)(150.0 mL) = ( M)(V2)
V = mL
Volume of H2O added =
1200 mL
– mL
= mL