Conductometric titration theory states that the end-point of the titration process is determined by means of measuring conductivity. This theory is used for colloids that have ionazable functional groups like latexes. These functional groups are acidic and the theory uses sodium hydroxide as a titrant. To test conductometric titration theory, add sodium hydroxide from the burette, then plot the conductivity readings that correspond to the increments against the titrant’s volume.
Benefits of the Theory
Conductometric titration theory can be used for either turbid or colored liquids in cases when you cannot detect the end-point by using indicators that are normal. Furthermore, you can use the theory to find out the end-points of dilute weak acids and solutions. Another advantage is that you do not need to measure the real conductance value because you can put into use any amount that is proportional to it.
The Theory’s Apparatus
The two essential tools used in the conductometric titration theory include an apparatus for measuring and studying conductivity changes and a conductivity cell that has dipping electrodes. But if you are carrying out simple titration using this theory, you will need a dipping electrode, a mechanical stirrer and a beaker of a suitable size. You will also require measuring circuits that will assist you in preventing concentration changes as a result of reactions at the electrodes.
Principles of the Theory
Principle of the conductometric titrations theory states that for dilutions that are infinite, ions act independently and in the process contribute toward conductance of the solution. The principle behind this theory states that anions and cations have different conductance values. Therefore, if you add a solution of one electrode to another, the final conductance will rely on the occurrence of reaction. But if there is no chemical reaction in the electrolyte solutions, there will be an increase in the level of conductance.
To calculate the end-point of the conductometric titration method, you should plot the curve of the conductometric titration in the usual way. Estimate the end-point by plotting two straight lines using the usual graphical method.
About the Author
Harold Debbi has been writing professionally since 2001. His articles have featured in the "Daily Express," "Good Housekeeping," "The Mirror" and "The People." Debbi holds a Masters of Arts in journalism from the University of Cambridge.