ABSTRACT: The aim of this general chemistry laboratory exercise is to teach students how to prepare solutions of known concentration from a solid (NaCl) and by dilution from a stock solution. After preparing the solutions, the students perform conductivity measurements to check the accuracy of the concentrations. Using Kohlrausch's law and the conductivity data, they back-calculate the concentration. The students also measure the conductivity of a weak electrolyte (CH3COOH) solution at the same concentration as the NaCl solution to better understand the difference between a strong and a weak electrolyte.