Barium sulfate, for example, is insoluble and remains as BaSO4 (s) when added to water, and thus cannot affect the concentration of the water. Magnesium hydroxide is only slightly soluble, so even though the ions conduct well, their concentration is low and there is little conductance in a solution above solid Mg(OH)2.

1. Conductivity titrations-CHM 240
By Dr. Robert D. Craig, Ph.D.
.

2. Conductivity titrations-CHM 240
• The electric conductivity of aqueous
electrolyte solutions is determined by the type
and number of charge carriers at constant
temperature.
• Characteristic changes in conductivity are
connected with changes in the ionic
composition of reacting systems.

3. Conductivity titrations-CHM 240

4. Conductivity titrations-CHM 240

5. What you can learn about . .
Electrolyte
Electrical conductance
Specific conductance
Ion mobility
Ion conductivity
Conductometry
Volumetry

6. . Conductivity titrations-CHM 240

7. .
• The basic unit of conductivity is the siemens
(S), formerly called the mho.

8. .
• . Since cell geometry affects conductivity
values, standardized measurements are
expressed in specific conductivity units (S/cm)
to compensate for variations in electrode
dimensions

9. .
• Specific conductivity (C) is simply the product
of measured conductivity (G) and the
electrode cell constant (L/A), where L is the
length of the column of liquid between the
electrode and A is the area of the electrodes
(see Figure 1).
• C = G x (L/A)

10. C = G x (L/A)

11. Conductivity titrations-CHM 240

12. Experimental setup of coulometric
titration “Start of titration”

13. measure the change in conductivity in
the titrations of the following:
• approximately 0.1 molar barium hydroxide
solution with 0.1 molar sulphuric acid,
• approximately 0.1 molarhydrochloric acid with
0.1 molar sodium hydroxide solution and
• approximately 0.1 molar acetic acid with 0.1
molar sodium hydroxide solution
• Other samples can alternatively be set in
advance for conductiometric determination of
their concentration contents.

14. Websites used
• http://www.eutechinst.com/techtips/tech-
tips25.htm

15. Websites used
• http://www.phywe.com/461/pid/26717