Re: Is there a relationship between pH and the conductivity of a liquid

Dear Brandon; Yes, there is a relation between the pH and the electrical current flow [the conductivity] of a solution, but there are other factors that affect the conductivity. This topic, the conductivity of solutions, takes up a full chapter in a textbook on physical chemistry with many graphs and numerical tables. But I will try to keep it simple, basic, non-mathematical, - and short. When an electrical current passes through a wire, what actually moves and carries the curent is ELECTRONS. But in solutions, the current is carried by IONS: positively charged CATIONS [+]such as H+ , Na+, Mg+, etc. and negative ANIONS [-]such as OH-, Cl-, Acetate-, etc. [The + and - should be superscripts, but this computer cant show this [maybe it can, but I cant]. The conductivity of a solution depends on the concentration of ALL the ions present, the greater their concentrations, the greater the conductivity, These ions all have the electrical unit charges shown by their symbols, but they move at different velocities [mobilities] through the solution, so they contribute differently to the conductivity. An analogy would be a line of persons carrying water to a tank, they all have the same size bucket, but some walk faster than others [i.e. have greater mobility]so they contribute more. These relative mobilities have been measured and are listed in many chemistry texts and reference books. Of the common ions, the most mobile CATION is the Hydrogen ion [H+] with a value of 350 units, and the most mobile ANION is the Hydroxyl ion [OH-], 199 units. The other common ions have values ranging between 40 and 80 units. So you se that strongly acidic [or strongly basic] solution will have high conductivity Since the pH is a measure of the concentration of the Hydrogen [and the Hydroxyl] ions, for an acidic solutin, the lower the pH [i.e. the higher the H+ concentration,] the greater the conductivity will be. Remember, the conductivity is the sum of the contribution of ALL the ions present in the solution I hope this brief discussion helps you. For more detailed information, I suggest a good encyclopedia, such as the Brittanica. Regards from Charlie Crutchfield