Factors Affecting Conductivity

Nature of Electrolyte

Conductivity of an electrolyte depends upon the nature of electrolyte.

(i) Weak or strong electrolyte: A weak electrolyte furnishes fewer ions therefore it has lower conductivity than a strong electrolyte of same concentration.

(ii) Valency of the ions: The ions with higher valency carry more charge and therefore they conduct more charge than the ion of lower valency. Thus higher the valency of the ion greater is the conducting power.

(iii) Speed of the ion: The ion which can move faster will carry the charge faster and therefore has more conducting power.

Temperature

Conductivity of an electrolyte generally increases by 2 to 3 percent for each degree rise in temperature. With increase in temperature the viscosity of the solvent decreases and thus ion can move faster. In case of weak electrolyte, when the temperature is increased its degree of dissociation increases, thus conductivity increases.

Concentration

(i) Variation of conductivity (k) with concentration: When the solution is diluted its conductivity also decreases. It is because k is the conducting power of all the ions present per cm³ of the solution. When the solution is diluted the number of ions per cm³ also decreases, hence k decreases.

(ii) Variation of Molar and Equivalent conductivity with concentration: As the solution is diluted its molar conductivity increases.