Question

How does dilution affect conductivity?

Answer 1

Ionic compounds are good conductors in their aqueous state. This is because ionic compounds have the tendency to dissociate into their aqueous solutions and act as electrolytes.

Complete step-by-step answer: An ionic solution is prepared by dissolving the ionic compound into an aqueous medium. This ionic solution has ions that have the capability to conduct electricity. The concentration or the amount of these ions has an effect on the conductivity of the solution.
The number of ions present in one cubic centimeter of the solution defines the specific conductivity of the solution. Different cases of dilution and its effect on conductivity of the ionic solution are:
-When the ionic solution is diluted, the number of ions per cubic centimeter decreases. So, the specific conductivity has a decrease when the solution is diluted.
-On the other hand, molar conductivity, which is the conductivity of the total ions present in 1 gram per mole of the solution increases when the solution is diluted. This is because it is the overall conductivity of the ions present in solution.
-When strong electrolytes are added, the molar conductivity increases on dilution as they dissociate or ionizes completely and increase the mobility of ions.
-Also when weak electrolytes are added which dissociate partially, increases the molar conductivity of solution on dilution as the ions become more mobile.
Hence, on dilution, the specific conductivity decreases and molar conductivity increases.

Note: Strong electrolytes dissociate completely, while weak electrolytes dissociate partially. This affects the conductivity of the solution, but their concentration or amount may have the same effect on conductivity as they both produce ions on dissociation.