- 10 -
Dilutions
By Half
By Tenth
ed
Simple Dilution
Proportional dilution
Serial Dilutions
Z
ah
Serial dilution by Half
Ratio (1:1)
To reduce any concentration by half just take any volume of the given concentration and add equal volume of water
10cm3 of
W
ad
a
El
10cm3 of
4% G
4%
N
2%
20cm3 of
4% G
4%
20cm3 of
W
2%
Same ratio but with different volumes
- 11 -
Way 1:
40cm3 of
4% G
20cm3 of
4% G
20cm3
of W
20cm3 of
2% G
20cm3
of W
20cm3 of
1% G
20cm3
of W
40cm3 of
2% G to
use
Way 2:
20cm3 of
4% G
20cm3
of W
ad
a
40cm3 of
4% G
40cm3 of
1% G to
use
40cm3 of
0.5% G to
use
20cm3
of W
20cm3 of 20cm3
1% G
of W
N
20cm3 of
2% G
20cm3 of
4% G to
use
20cm3 of
2% G to
use
40cm3 of
0.25% G to
use
El
40cm3 of
4% G to
use
Z
ah
ed
20cm3 of 20cm3
1% G
of W
20cm3 of
1% G to
use
20cm3 of
0.5% G to
use
20cm3 of
1% G
20cm3
of W
40cm3 of
0.25% G to
use
- 12 -
Serial dilution by Tenth
Ratio (1:9)
To reduce any concentration by tenth just take 1 cm3 of the given concentration and add 9cm3 water
9cm3 of W
10%
100%
Z
ah
ed
1cm3 of
100% G
Same ratio but with different volumes
El
18cm3 of W
ad
a
2cm3 of
100% G
N
100%
10%
- 13 -
Way 1:
10cm3 of
100% G
1cm3 of
100% G
9cm3
of W
1cm3 of 9cm3 of
W
10% G
9cm3
of W
1cm3 of
0.1% G
9cm3
of W
10cm3 of
10% G to
use
Way 2:
10cm3 of
100% G
1cm3 of
100% G
9cm3
of W
10cm3 of
1% G to
use
10cm3 of
0.1% G to
use
10cm3 of
0.01% G to
use
El
10cm3 of
100% G to
use
Z
ah
ed
1cm3 of
1% G
1cm3 of
1% G
9cm3
of W
1cm3 of
0.1% G
9cm3
of W
N
ad
a
1cm3 of 9cm3 of
W
10% G
9 cm3 of
100% G to
use
9 cm3 of
10% G to
use
9 cm3 of
1% G to
use
9 cm3 of
0.1% G to
use
9 cm3 of
0.01% G to
use
- 14 -
Simple Dilution OR Propotional Dilution
In this type of dilution you will be asked to prepare any 5 different concentrations with constant
intervals in between but not Half nor tenth.
Examples
(7
(7.5-5.0-2.5-0.0)
by interval 2.5 %
10
(8
(8-6-4-2)
by interval 2%
1
(0
(0.8-0.6-0.4-0.2)
by interval 0.2 %
0.1
(0
(0.08-0.06-0.04-0.02)
by interval 0.02%
5
(4
(4-3-2-1)
by interval 1%
0.55
(0
(0.4-0.3-0.2-0.1)
by interval 0.1%
ed
10
Volume of
original
concentration
Z
ah
V1 C1= V2 C2
Original /
given
concentration
Final required
volume of the
new
Example 1:
X C1 =
X C2
?
X 10% = 10cm3 X 8%
ad
a
V2
El
V1
So V1= 8cm3
The new/required
concentration
2cm3
2
water
Volumes of water /cm3
Volumes of 10 % glucose solution/cm3
10
0
10
8
2
8
6
4
6
4
6
4
2
8
2
0
10
0
N
Percentage concentration of glucose solution
- 15 -
Example 2:
V1
X C1 =
V2
X C2
?
X 0.5 % = 5c
5cm3 X 0.4%
3
1c
1cm of water
ed
3
So V1=
1 4cm
4
Volumes of water /cm3
Volumes of 0.5% glucose solution/cm3
0.5
0
5
Z
ah
Percentage concentration of reducing sugar solution
0.4
0.3
0.2
4
2
3
3
2
4
1
N
ad
a
El
0.1
1