1. 3.2 – To dilute a solution of known
concentration to a given
concentration
DILUTIONS
2. To make a solution less concentrated
A dilute solution contains
less solute than a more
concentrated solution
Example: 5 g/L to 2 g/L
3. Use the following formula to dilute a
solution
Concentration of
original solution
Volume of
original solution
Concentration of
“new” solution
Volume of
“new” solution
11 2 2VC V C
4. Given 550 mL of a calcium chloride
water solution concentrated to
15g/L, what will be its concentration
if we add 50 mL of water to the
solution?
0.5 L
C1 x V1 = C2 x V2
Write down all information
Original Sol. New (diluted) Sol.
1
1
15 /
.55
C g L
V L
2
2
?
.600
C
V L
0.55 + 0.050
= 0.60 L
5. 0.5 L
1
1
15 /
.55
C g L
V L
2
2
?
.600
C
V L
Set up formula and solve
C1 x V1 = C2 x V2
15 x .55 = C2 x 0.60
8.25 = 0.60C2
C2 = 13.75 g /L
6. What is the volume of a 70 g/L
solution if, after diluting it to a
volume of 4 L, its new
concentration becomes 15 g/L
0.5 L
C1 x V1 = C2 x V2
Write down all information
Original Sol. New (diluted) Sol.
1
1
70 /
?
C g L
V
2
2
15 /
4
C g L
V L
7. 0.5 L
Set up formula and solve
C1 x V1 = C2 x V2
70 x V1 = 15 x 4
70V1 = 60
V1 = 0.86 L
1
1
70 /
?
C g L
V
2
2
15 /
4
C g L
V L
8. A 250mL solution of orange juice is too strong.
100mL of water is added, to give the orange
juice a concentration of 10g/L. What was the
original concentration of the orange juice
before it was diluted?
Write down all information
Original Sol. New (diluted) Sol.
C1 = ?
V1 = 0.25L
C2 = 10 g/L
V2 = 0.35L
C1 x V1 = C2 x V2
(C1)(0.25) = (10)(0.35)
(C1)(0.25) = (3.5)
C1 = 14 g/L
9. 1.5L of a 12.75g/L salt solution is
diluted to a concentration of 10g/L.
What is the final volume of the
diluted solution?
C1 = 12.75g/L
V1 = 1.5 L
C2 = 10 g/L
V2 = ?
C1 x V1 = C2 x V2
(12.75)(1.5) = (10)(V2)
(19.125) = (10)(V2)
V2 = 1.9125 L
10. A 500mL solution with a concentration
of 2.5g/L is diluted to a concentration of
0.25 g/L. How much water was added
in order to dilute the original solution?
C1 = 2.5 g/L
V1 = 0.5 L
C2 = 0.5 g/L
V2 = ?
C1 x V1 = C2 x V2
(2.5)(0.5) = (0.25)(V2)
V2 = 5 L
5L – 0.5L = 4.5L
This is the FINAL volume, not
how much was added!!!
4.5 L of
water was
added
11. You have 400mL of salt solution and
add TWO 200mL containers of water to
obtain a new concentration of 200 g/L.
What was the original concentration in
g/L?
C1 = ?
V1 = 0.4 L
C2 = 200 g/L
V2 = 0.8 L
C1 x V1 = C2 x V2
(C1)(0.4) = (200)(0.8)
C2 = 400 g/L
Recall, you
added
400mL to
the 400mL
12. You have 500mL of a 10g/L
solution and want to dilute it to a
concentration of 2g/L. What procedure
would you perform in order to carry out
this dilution?
C1 x V1 = C2 x V2
(10)(0.5) = (2)(V2)
V2 = 2.5L
Carry out calculations.
Write out procedure.
1st – Take the 0.5L of
10g/L solution
2nd – Then ADD 2L of
water to obtain 2.5L
new diluted
concentration of
2g/L.
FINAL volume. So, 2L of water
was ADDED to the original 0.5L
13. You have 12g/L solution and you
dilute it to a concentration of 4g/L. The
volume of the diluted solution is 3L.
Explain how to carry out such a dilution.
C1 x V1 = C2 x V2
(12)(V1) = (4)(3)
V1 = 1L
Carry out calculations.
Write out procedure.
1st – Take the 1L of
12g/L solution
2nd – Then ADD 2L of
water to obtain 3L
new diluted
concentration of
4g/L.
INITIAL volume of concentrated
solution
14. read question carefully and fill in all
information before beginning
you will always be given 3 out of
the 4 variables in the
equation…solve for the unknown
do not forget that V2 is the FINAL
volume of new solution
(original solution + water added
to dilute it!)
15. Key Points:
A dilution means to make LESS
concentrated
Formula: C1 x V1 = C2 x V2
Recall, V2 is the final volume
Know the procedure to carry out a
dilution!
16. Worksheet # 5
Study guide, Module 3, page 16
AFTER YOU HAVE COMPLETED AND UNDERSTAND THESE
TYPES OF PROBLEMS…….PROCEED TO THE NEXT SLIDES TO
TRY SOME TRICKIER PROBLEMS!!!
17.
18. You have 2 different solutions of
different concentrations. Which
solution is more concentrated?
Solution Concentration
#1 10g/100mL
#2 10g/L
Can’t compare concentration if have different units!!!
So, put everything into g/L:
10g/100mL 10g/0.1L 100g/L
100g/L
Recall 1000mL = 1L
19. You have 3 different solutions of
different concentrations. Rank from
most to least concentrated.
Solution Concentration
#1 10g/L
#2 10% m/V
#3 10g/10mL
Can’t compare concentration if have different units!!!
10% m/V 10g/100mL 10g/0.1L
100g/L
100g/L
10g/10mL 10g/0.01L 1000g/L
1000g/L
Most to least concentrated:
#3, #2 then #1
20. A 4L sugar solution has a
concentration of 25% (m/v). The
solution is diluted to a concentration of
10% (m/v). What is the volume of the
diluted solution?
C1 = 250 g/L
V1 = 4 L
C2 = 100 g/L
V2 = ?
C1 x V1 = C2 x V2
(250)(4) = (100)(V2)
V2 = 10 L
Recall 25% =
25g/100mL =
25g/0.1L =
250 g/L
21. A salt solution has a concentration of
40% (m/V). The solution is diluted to a
concentration of 25% (m/V) and has a
volume of 1.2L. What is the volume of
the concentrated solution?
C1 = 400 g/L
V1 = ?
C2 = 250 g/L
V2 = 1.2L
C1 x V1 = C2 x V2
(400)(V1) = (250)(1.2)
V1 = 0.75 L
or
750 mL
Recall 40% =
40g/100mL =
40g/0.1L =
400 g/L
Recall 25% =
25g/100mL =
25g/0.1L =
250 g/L
22. Key Points:
In order to compare concentrations or to
do dilutions, ALL concentrations must
be in the SAME UNITS:
g/L
1g/100mL = 1g/0.1L = 10g/L
1% m/V = 1g/100mL = 1g/0.1L = 10g/L
These are SNEAKY!!!
23. Worksheet # 6 (tricky problems!)
(review of both concentration and dilution problems)
