Precise measurement of W, the average energy expended per ion pair found in the alcohols and water

W values for the low molecular weight aliphatic alcohols and water were determined by measuring a saturation current resulting from the total deposition of energy by a Ni[raised 63] source. Such measurements were determined relative to that of nitrogen with an experimental precision of approximately 0.5%. Difficulties were encountered in achieving total ion collection which were not manifested by a deviation from linearity of plots of the saturation current as a function of voltage. A temperature and a pressure effect upon.the saturation currents were noted but were attributed to incomplete collection of the ion pairs formed. Good correlation was noted between the W(alcohol) values and those for the alkanes when the hydroxyl group was substituted for a methyl group, but poor correlation was noted with a substitution for a hydrogen atom. Energy balance considerations show that about two thirds of the energy expended in the alcohols, goes to ionization while the remaining third is expended in molecular excitation.