Question

When water is added to an aqueous solution of an electrolyte, what is the change in specific conductivity of the electrolyte?

• A. Conductivity decreases
• B. Conductivity increases
• C. Conductivity remains same
• D. Conductivity does not depend on number of ions

Answer 1

The correct option is A Conductivity decreases

Factors affecting electrolytic conductance are:

• Concentration of ions: The sole reason for the conductivity of electrolytes is the ions present in them. The conductivity of electrolytes increases with an increase in the concentration of ions as there will be more charge carriers if the concentration of ions is more and hence the conductivity of electrolytes will be high.
  

• Nature of electrolyte: Electrolytic conduction is significantly affected by the nature of electrolytes. The degree of dissociation of electrolytes determines the concentration of ions in the solution and hence the conductivity of electrolytes. Substances such as $C{H}_{3}COOH$, with a small degree of separation, will have less number of ions in the solution and hence their conductivity will also below, and these are called weak electrolytes. Strong electrolytes such as $KN{O}_3$ have a high degree of dissociation and hence their solutions have a high concentration of ions and so they are good electrolytic conductance.
  

• Temperature: Temperature affects the degree to which an electrolyte gets dissolved in solution. It has been seen that higher temperature enhances the solubility of electrolytes and hence the concentration of ions which results in an increased electrolytic conduction.
  

When water is added to an aqueous solution the number of ions per unit volume decreases i.e. the concentration of ions decreases and hence thereby conductivity gets decreased.