Quinhydrone Electrode in Amyl Alcohol Solutions¹

Abstract

from rains. All handling of apparatus should be done in as cool a place as possible and out of direct sunlight. In direct hot sunlight the end point is vague, and it is difficult and sometimes impossible to obtain reasonable accuracy. Solutions of iodine and starch carried in the field should be protected from light and heat by covering the bottles with thick toweling, which is kept damp with water. Frequency of DeterminationsAn operator familiar with the manipulation of the apparatus can make one complete determination in about 3 minutes.It is the best practice to make determinations at 4or 5-minute intervals, using the hourly averages for studying the general trend. Such determinations, made at exactly equal

Potentiometric Determination of Acidity in Insulating Oils

“…Known acids were dissolved in oil with subsequent determination of neutralization number in order to compare the results obtained employing four different procedures-namely, A. S. T. M. using methyl alcohol as a solvent, A. S. T. M. using ethyl alcohol as a solvent, alkali blue, and electrometric. The latter method was carried out with the two previously described reference electrodes (5,6). The concentration The estimation of acidity in oils employing the alkali blue procedure has been found to give more satisfactory results than the A. S. T. M. procedure.…”

Potentiometric Titration in Nonaqueous Solutions

“…This instrument also made possible the elimination of neutral salts such as lithium chloride, which have heretofore been used to reduce the resistance of butyl alcohol solutions (4,5 ) . 05 N ) , prepared and stored as described in tassium or sodium hydroxide.…”

Potentiometric Titration in Non-Aqueous Solutions

“…Electrode System-The reference electrode was a saturated calomel half-cell, which made contact with the solution through an agar-agar salt bridge. The agar-agar mixture (7) was added while hot to a tube 15 cm. by 6 mm.…”

“…Seitz and McKinney (7) suggested for the potentiometric titration of oil acidity a method using amyl alcohol saturated with lithium chloride as a solvent and also as the reference electrode, quinhydrone being added to both half-cells. Bright platinum electrodes were used.…”