SOME SOURCES OF ERROR IN VISCOSITY MEASUREMENT
Journal of the American Chemical Society
The temperature coefficients of these groups at 18' were 0.00026~, 0 . 0 0 0 2 8 5 , and 0.000290. From these results it is obvious that the temperature coefficient of the electxomotive force of the combination changes very little with the concentration of the solution, although the voltages obtained are much higher than in the case of the saturated element. Summary. The possibility of employing calomel as depolarizer in the construction of precision standard cells has been established.
... stablished. Ordinary calomel, when suitably modified so as to contain finely divided mercury, giving the material a gray color, forms a depolarizer for cells, gives constant and reproducible electromotive forces, and this preparation should give better results in calomel electrodes. Saturated and unsaturated cells of composition Hg I HgClz 1 CdClz I Cd amalgam have been constructed, their E. M. F.'s measured and their temperature coefficients obtained. The thermodynamics of the saturated combination has been investigated and satisfactory agreement between the heat of the reaction as calculated from the electromotive force data and that obtained from thermo-calomel measurements has been established.