Conductivity of strong and weak electrolytes with Cobra SMARTsense

Principle

It is possible to differentiate between strong and weak electrolytes by measuring their electrical conductance. Strong electrolytes follow Kohlrausch's law, whereas weak electrolytes are described by Ostwald's dilution law. The examination of the concentration dependence of the conductivity allows the molar conductivities of infinitely diluted electrolytes to be determined, and facilitates the calculation of degree of dissociation and the dissociation constants of weak electrolytes.

Benefits

• With detailed experiment guide
• Simplified implementation: all pre-settings already prepared
• Easy evaluation via software

Tasks

1. Determine the concentration dependence of the electrical conductivity of potassium chloride and acetic acid solutions.
2. Calculate the molar conductivity and determine the molar conductivity at infinite dilution by extrapolation.

Learning objectives

• Kohlrausch's law
• Equivalent conductivity
• Temperature-dependence of conductivity
• Ostwald's dilution law

Necessary accessories

• Precision balance 620g/0.001g

Software included. Computer not provided.