Date of Award


Document Type

Open Access

Degree Name

Masters of Science



First Advisor

Jermain D. Porter

Second Advisor

Robert W. Schaefer




Voltarnmetry with a mercury pool cathode has been examined using both slow and rapid scanning techniques. A conventional polarograph was used to interpret the slow scans, and a cathode ray polarograph for the rapid scans. A description of the necessary apparatus is given as well as the experimental details involved.

Three different supporting media were studied: 0.01 molar potassium nitrate, 0.1 molar potassium acid phthalate, and 0.1 molar ammonia-0.1 molar ammonium chloride. Well defined peaks were observed for lead, cadmium, and zinc in potassium nitrate. Indium also gave a peak, but it was not characteristic of a three-electron reduction. Furthermore, indium solutions on standing gave lower peaks, probably owing to hydrolysis. A copper peak was found in this medium, but the start of the peak was ill defined, thus preventing an accurate measurement of the peak current.

In 0.1 molar potassium acid phthalate copper, lead, cadmium, indium, and zinc produced well defined peaks. Bismuth yielded a very sharp peak, but the peak ix current was erratic.

Solutions of 0, 1 molar ammonium-0.1 molar ammonium chloride proved satisfactory for copper, cadmium, nickel, cobalt, and zinc. The peaks due to cobalt and nickel preceded the zinc reduction by a sufficient voltage to allow their determination in the presence of zinc. The standard deviation for analyses conducted on different days varied from two to five per cent depending on the ion being studied. The peak currents for the various ions are compared and the half peak potentials listed.

Included in

Chemistry Commons



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In Copyright - Educational Use Permitted.