Date of Award


Document Type

Union College Only

Degree Name

Bachelor of Science






The general purpose of this investigation, as well as many other investigations made on silicic acid gels at Union College, has been to obtain data which may help to formulate an idea of the gel structure and the process of setting of silicic acid gels. The specific object of the research was to determine whether or not the quinhydrone electrometric set-up for measuring the pH of a solution gives the correct pH of a solution in which there is silicic acid gel present. Since a large amount of data has been taken in connection with silicic acid gels in the measurement of pH by the quinhydrone electrode, it was desired that through tests be made to determine whether the silicic acid gel has any effect on the quinhydrone. If it were discovered that the silicic acid gels had any effect on the quinhydrone, it would be necessary to discard the pH data on the silicic acid gels that had been previously collected using the quinhydrone electrode. It was thought that, since silicic acid gels have high absorptive power for certain molecules, they might possibly absorb either the quinone or the hydro-quinone and thus destroy the equimolecular equilibrium between these two components. Since the success of the quinhydrone electrode depends on the fact that in solution quinone and hydro-quinone form an equimolecular chemical compound, C6H4O2 ⋅ C6H4(OH)2 called quinhydrone, a very slight absorption of either component would change the potential of the quinhydrone electrode and also the indicated value of the pH of the solution which is proportional to quinhydrone electrode potential. The next work was to determine whether there is any change in the pH of a silicic acid gel during or after setting.