APPARATUS REQUIRED
1) Conductivity cell
2) Conductivity bridge
3) Burette and pipette.
CHEMICAL REQUIRED
1) 0.1N NaOH (50ml)
2) 0.1N HCL (10ml)
3) Deionized water or Conductivity water
THEORY
Conductometric titration is one of electrometric methods of measurement of
concentration of on electrolyte solut. by findy.
out the conductances at various stage
of tituation. A conductometric titration curve
is obtained by platting graphically the
conductance against the volume solution added from the burette. The point of break or
intersection point in the conductometric
titration curve gives the end point of titration
When a strong acid e.g. Hel taken in a beaker
and titrated with strong acid base e.g. NaoH
the following rexn occurs
concentration of on electrolyte solut. by findy.
out the conductances at various stage
of tituation. A conductometric titration curve
is obtained by platting graphically the
conductance against the volume solution added from the burette. The point of break or
intersection point in the conductometric
titration curve gives the end point of titration
When a strong acid e.g. Hel taken in a beaker
and titrated with strong acid base e.g. NaoH
the following rexn occurs
H+ + Cl- + Na+ + OH- ➡️ Na+ + Cl- + H2O
Here, in titration, the fast moving H+ ions are
substituted by slow the conductance decreasing Na+ ions and the equivalent point. After equivalent point. gradually up to
the addition of NaoH provides the fast moving
Our and also Na+ ions with the increase of
their conct. So conductance increases more steepless. The minimum of conductance during fitration gus the equivalent point of the conductance should vary as rexn
substituted by slow the conductance decreasing Na+ ions and the equivalent point. After equivalent point. gradually up to
the addition of NaoH provides the fast moving
Our and also Na+ ions with the increase of
their conct. So conductance increases more steepless. The minimum of conductance during fitration gus the equivalent point of the conductance should vary as rexn
In the titration, as the mobilities of substituted and substituting ions but it should not as dilution and to minimize the effect vary. dilution the reagent of the burette should The
at least 10 times concentrated than the
reagent of the conductivity bottle.
at least 10 times concentrated than the
reagent of the conductivity bottle.
PROCEDURE
1. Clean burette was filled with O.1N NaOH solution2. Pipette 10ml of the given HCL in 100ml beaker and add 90ml distilled water to make it
approximately 10 times more dilute than reagent of burette so that affect dilution
was minimized. Then we calibrated the
Conductometer with the help of standard
buffer of known specific conductance and then placed the conductivity cell of known cell constant such that electrodes tre dipped completely, in given acid solution. The cell was then connected to conductivity bridge. The conductance of HCL solution at addition of Nach Solution was noted, Conductometric tiltuation was continued. until the two limbs of titration curve could be treated clearly. Temp" was maintained at: 31°c
Observation
|
Volume of NaoH (ml) from burette |
Conductance |
|
0 |
4.25 |
|
0.5 |
4.1 |
|
1 |
3.5 |
|
1.5 |
3.43 |
|
2 |
3.08 |
|
2.5 |
2.81 |
|
3 |
2.40 |
|
3.5 |
2.26 |
|
4 |
2.05 |
|
4.5 |
1.715 |
|
5 |
1.5 |
|
5.5 |
1.44 |
|
6 |
1.28 |
|
6.5 |
1.36 |
|
7 |
1.44 |
|
7.5 |
1.51 |
|
8 |
1.78 |
|
8.5 |
1.98 |
|
9 |
2.20 |
|
9.5 |
2.40 |
|
10 |
2.74 |
|
10.5 |
2.88 |
|
11 |
3.01 |
|
11.5 |
3.22 |
|
12 |
3.3 |
Graph
In x-axis 1 bigbox - 1ml
In y-axis 1 big box = 0.5ms
Original Graph
 |
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