Vol. of NaOH pH

0.2 3.50.4 3.50.7 3.550.8 3.61 3.7

1.2 3.81.4 3.91.6 3.951.8 4.032 4.1

2.2 4.12.4 4.152.6 4.192.8 4.223 4.29

3.2 4.323.4 4.353.6 4.373.8 4.394 4.4

4.2 4.464.4 4.54.6 4.544.8 4.575 4.6

5.2 4.63

Vol. of NaOH pH

5.4 4.675.6 4.75.8 4.736 4.75

6.2 4.786.4 4.86.6 4.836.8 4.867 4.9

7.2 4.957.4 4.987.6 57.8 5.028 5.05

8.2 5.18.4 5.18.6 5.158.8 5.29 5.22

9.2 5.299.4 5.39.6 5.389.8 5.410 5.45

10.2 5.4510.4 5.5210.6 5.6

Vol. of NaOH pH

10.8 5.6511 5.7

11.2 5.7511.4 5.911.6 611.8 6.0312 6.15

12.2 6.412.4 6.8512.6 9.112.8 10.413 10.5

13.2 10.6913.4 10.813.6 10.913.8 1114 11.3

14.2 11.0914.4 11.1214.6 11.1514.8 11.1715 11.2

15.2 11.2415.4 11.2815.6 11.3315.8 11.416 11.5

Table : pH titration of CH3COOH with NaOH

Table : Determination of ∆ pH∇V

for acetic acid

Vol. Range of NaOH ∆V mean volume ∆pH ∆pH/∆V.02-.4 0.2 0.3 0 0

0.4-0.7 0.3 0.55 0.05 0.1666666670.7-0.8 0.1 0.75 0.05 0.50.8-1.0 0.2 0.8 0.1 0.51.0-1.2 0.2 1.1 0.1 0.51.2-1.4 0.2 1.3 0.1 0.51.4-1.6 0.2 1.5 0.05 0.251.6-1.8 0.2 1.7 0.08 0.41.8-2.0 0.2 1.9 0.07 0.352.0-2.2 0.2 2.1 0 02.2-2.4 0.2 2.3 0.05 0.252.4-2.6 0.2 2.5 0.04 0.22.6-2.8 0.2 2.7 0.03 0.152.8-3.0 0.2 2.9 0.07 0.353.0-3.2 0.2 3.1 0.03 0.153.2-3.4 0.2 3.3 0.03 0.153.4-3.6 0.2 3.5 0.02 0.1

3.6-3.8 0.2 3.7 0.02 0.13.8-4.0 0.2 3.9 0.01 0.054.0-4.2 0.2 4.1 0.06 0.34.2-4.4 0.2 4.3 0.04 0.24.4-4.6 0.2 4.5 0.04 0.24.6-4.8 0.2 4.7 0.03 0.154.8-5.0 0.2 4.9 0.03 0.155.0-5.2 0.2 5.1 0.03 0.155.2-5.4 0.2 5.3 0.04 0.25.4-5.6 0.2 5.5 0.03 0.155.6-5.8 0.2 5.7 0.03 0.155.8-6.0 0.2 5.9 0.02 0.16.0-6.2 0.2 6.1 0.03 0.156.2-6.4 0.2 6.3 0.02 0.16.4-6.6 0.2 6.5 0.03 0.156.6-6.8 0.2 6.7 0.03 0.156.8-7.0 0.2 6.9 0.04 0.27.0-7.2 0.2 7.1 0.05 0.257.2-7.4 0.2 7.3 0.03 0.157.4-7.6 0.2 7.5 0.02 0.17.6-7.8 0.2 7.7 0.02 0.17.8-8.0 0.2 7.9 0.03 0.158.0-8.2 0.2 8.1 0.05 0.258.2-8.4 0.2 8.3 0 08.4-8.6 0.2 8.5 0.05 0.258.6-8.8 0.2 8.7 0.05 0.258.8-9.0 0.2 8.9 0.02 0.19.0-9.2 0.2 9.1 0.07 0.359.2-9.4 0.2 9.3 0.01 0.059.4-9.6 0.2 9.5 0.08 0.49.6-9.8 0.2 9.7 0.02 0.1

9.8-10.0 0.2 9.9 0.05 0.2510-10.2 0.2 10.1 0 0

10.2-10.4 0.2 10.3 0.07 0.3510.4-10.6 0.2 10.5 0.08 0.410.6-10.8 0.2 10.7 0.05 0.2510.8-11.0 0.2 10.9 0.05 0.2511.0-11.2 0.2 11.1 0.05 0.2511.2-11.4 0.2 11.3 0.15 0.7511.4-11.6 0.2 11.5 0.1 0.511.6-11.8 0.2 11.7 0.03 0.1511.8-12.0 0.2 11.9 0.12 0.612.0-12.2 0.2 12.1 0.25 1.2512.2-12.4 0.2 12.3 0.45 2.2512.4-12.6 0.2 12.5 2.25 11.2512.6-12.8 0.2 12.7 1.3 6.5

12.8-13.0 0.2 12.9 0.1 0.513.0-13.2 0.2 13.1 0.19 0.9513.2-13.4 0.2 13.3 0.11 0.5513.4-13.6 0.2 13.5 0.1 0.513.6-13.8 0.2 13.7 0.1 0.513.8-14.0 0.2 13.9 0.3 1.514.0-14.2 0.2 14.1 0.09 0.4514.2-14.4 0.2 14.3 0.21 1.0514.4-14.6 0.2 14.5 0.03 0.1514.6-14.8 0.2 14.7 0.02 0.114.8-15.0 0.2 14.9 0.03 0.1515.0-15.2 0.2 15.1 0.04 0.215.2-15.4 0.2 15.3 0.04 0.215.4-15.6 0.2 15.5 0.05 0.2515.6-15.8 0.2 15.7 0.07 0.3515.8-16.0 0.2 15.9 0.1 0.516.0-16.2 0.2 16.1 0 0

Graph 2:∆ pH∇V

vs mean value (of NaOH volume) curve

Table : pH titration of Succinic acid with NaOH

∆ pH∇V

Y axis

Vol. of NaOH (ml) pH0.2 3.550.4 3.580.6 3.60.8 3.651 3.69

1.2 3.731.4 3.761.6 3.81.8 3.92 3.95

2.2 3.982.4 4.022.6 4.12.8 4.153 4.18

3.2 4.223.4 4.283.6 4.343.8 4.424 4.5

4.2 4.554.4 4.64.6 4.654.8 4.735 4.75

5.2 4.825.4 4.875.6 4.955.8 4.986 5.02

6.2 5.16.4 5.156.6 5.26.8 5.257 5.31

7.2 5.387.4 5.47.6 5.45

7.8 5.528 5.6

8.2 5.658.4 5.78.6 5.758.8 5.839 5.9

9.2 69.4 6.029.6 6.19.8 6.1810 6.28

10.2 6.410.4 6.6210.6 6.9210.8 811 9.8

11.2 10.311.4 10.511.6 10.711.8 10.8212 10.9

Graph 3: pH titration of succinic acid with NaOH solution

Table: Determination of ∆pH/∆V for succinic acid.

Range ∆V Mean value ∆pH ∆pH/∆V0.2-0.4 0.2 0.3 0.03 0.150.4-0.6 0.2 0.5 0.02 0.10.6-0.8 0.2 0.7 0.05 0.250.8-1.0 0.2 0.9 0.04 0.21.0-1.2 0.2 1.1 0.04 0.21.2-1.4 0.2 1.3 0.03 0.151.4-1.6 0.2 1.5 0.04 0.21.6-1.8 0.2 1.7 0.1 0.51.8-2.0 0.2 1.9 0.05 0.252.0-2.2 0.2 2.1 0.03 0.152.2-2.4 0.2 2.3 0.04 0.22.4-2.6 0.2 2.5 0.08 0.42.6-2.8 0.2 2.7 0.05 0.252.8-3.0 0.2 2.9 0.03 0.153.0-3.2 0.2 3.1 0.04 0.23.2-3.4 0.2 3.3 0.06 0.33.4-3.6 0.2 3.5 0.06 0.33.6-3.8 0.2 3.7 0.08 0.4

3.8-4.0 0.2 3.9 0.08 0.44.0-4.2 0.2 4.1 0.05 0.254.2-4.4 0.2 4.3 0.05 0.254.4-4.6 0.2 4.5 0.05 0.254.6-4.8 0.2 4.7 0.08 0.44.8-5.0 0.2 4.9 0.02 0.15.0-5.2 0.2 5.1 0.07 0.355.2-5.4 0.2 5.3 0.05 0.255.4-5.6 0.2 5.5 0.08 0.45.6-5.8 0.2 5.7 0.03 0.155.8-6.0 0.2 5.9 0.04 0.26.0-6.2 0.2 6.1 0.08 0.46.2-6.4 0.2 6.3 0.05 0.256.4-6.6 0.2 6.5 0.05 0.256.6-6.8 0.2 6.7 0.05 0.256.8-7.0 0.2 6.9 0.06 0.37.0-7.2 0.2 7.1 0.07 0.357.2-7.4 0.2 7.3 0.02 0.17.4-7.6 0.2 7.5 0.05 0.257.6-7.8 0.2 7.7 0.07 0.357.8-8.0 0.2 7.9 0.08 0.48.0-8.2 0.2 8.1 0.05 0.258.2-8.4 0.2 8.3 0.05 0.258.4-8.6 0.2 8.5 0.05 0.258.6-8.8 0.2 8.7 0.08 0.48.8-9.0 0.2 8.9 0.07 0.359.0-9.2 0.2 9.1 0.1 0.59.2-9.4 0.2 9.3 0.02 0.19.4-9.6 0.2 9.5 0.08 0.49.6-9.8 0.2 9.7 0.08 0.4

9.8-10.0 0.2 9.9 0.1 0.510.0-10.2 0.2 10.1 0.12 0.610.2-10.4 0.2 10.3 0.22 1.110.4-10.6 0.2 10.5 0.3 1.510.6-10.8 0.2 10.7 1.08 5.410.8-11.0 0.2 10.9 1.8 911.0-11.2 0.2 11.1 0.5 2.511.2-11.4 0.2 11.3 0.2 111.4-11.6 0.2 11.5 0.2 111.6-11.8 0.2 11.7 0.12 0.6

Graph 4: ∆pH/∆V vs mean volume curve

Calculation and Results:

Standardization of NaOH solution with standard 0.1 M Oxalic acid solution :

We know that,

2SaVa=SbVb

Or, Sb=2SaV aV b

=2×0.1M ×10ml

=

Determination of Ka for acetic acid:

End point volume=12.6 ml

pH at half volume (6.3ml) of end point = 4.75

now, pKa=4.75

or, -logKa=4.75

or, logka=-4.75

or, Ka=antilog(-4.75)

or, Ka=1.78×10-05

Determination of Ka for succinic acid:

End point volume=10.80 ml

pH at half volume (6.3ml) of end point = 4.87

now, pKa=4.87

or, -logKa=4.87

or, logka=-4.87

or, Ka=antilog(-4.87)

or, Ka=1.35×10-05

Discussion:

The deviation found in the experimental value of Ka and literature value is:

Chemicals Exp. Value Literature value DeviationAcetic acid 1.78×10-05 1.8×10-05

Succinic acid 1.35×10-05 6.3×10-05