Measurement of Conductlvity tn Ionic Solutions Chemistry Notes
Measurement of Conductivity in lonic Solutions :
→ The conductivity of given solution is measured by measuring its resistance with the help of Wheatstone’s bridge. Its composition can be altered due to electrochemical reaction on passing direct current in an ionic solution for a long time. But we can face two problems in measuring of resistance of ionic solution:
- The composition of solution can be changed on passing direct current (DC).
- Solution can not be attached to bridge like metallic wire or other solid conductor.
→ Solution of First Problem – Here, we use alternating current (AC) by which the polarity produced in one direction cancels flow of polarity produced in other direction and so the concentration of solution and its composition remain unchanged. Solution of Second Problem Here, we use an apparatus designed specifically for solving this problem. This apparatus is called conductivity cell. The conductivity cell is available in many designs among which two are as follows