206 CONDUCTIVITY AND VISCOSITY IN MIXED SOLVENTS. 



lithium bromide in 25 per cent methyl alcohol and water, in 50 per cent ethyl 

 alcohol and water, and in 50 per cent acetone and water. It is also true for 

 cobalt chloride, in 25 per cent methyl alcohol and water, in 50 per cent ethyl 

 alcohol and water, and in 75 per cent acetone and water. 



By reference to the work of Jones and Bingham 1 we see that this is likewise 

 true for lithium nitrate in 25 per cent acetone and water, for potassium iodide 

 in 50 per cent acetone and w r ater, and for calcium nitrate in 25 per cent and 

 50 per cent acetone and water. 



(8) The molecular conductivities of potassium sulphocyanate in acetone, 

 as compared with the corresponding conductivities in water, bring out some 

 important facts. The conductivity values in the N/10 solutions are usually 

 much smaller in acetone than they are in water, but with increase in dilution 

 they become very much larger in acetone than they do in water. The same 

 thing is seen to be true when the conductivity of the acetone solutions is com- 

 pared with the solutions in the alcohols, but to a smaller degree. The values 

 become greater in acetone than they do in either of the alcohols. 



(9) A marked minimum in fluidity has been noted in the following cases : 

 50 per cent methyl alcohol and water at and 25, 50 per cent ethyl alcohol 

 and water, 50 per cent acetone and water. 



(10) A maximum in fluidity has been noted in the following cases: In 

 75 per cent acetone and methyl alcohol at 0. Although this maximum has 

 disappeared at 25, yet there is a decided increase of the values in the mix- 

 ture above the average values; in N/10 potassium sulphocyanate in 75 per 

 cent acetone and ethyl alcohol at 0. The pure solvent does not show the 

 maximum at 0, and the maximum has entirely disappeared at 25 in both 

 the solution and the solvent, but nevertheless there is an increase above the 

 average values in each case in the 75 per cent mixture. This increase above 

 the average values is also shown by the mixtures of methyl alcohol and ethyl 

 alcohol. 



(11) A marked negative viscosity coefficient is shown by potassium sul- 

 phocyanate in aqueous solution. In the other pure solvents, methyl alcohol, 

 ethyl alcohol, and acetone, potassium sulphocyanate gives a positive viscosity 

 coefficient, and in mixtures of the other solvents with water the viscosity 

 coefficient becomes zero in the following mixtures : At a point about midway 

 between the 50 per cent and 75 per cent mixtures of methyl alcohol and water; 

 and in the same mixtures of ethyl alcohol and water, and between the 25 per 

 cent and 50 per cent mixtures of acetone and water. 



(12) The temperature coefficients of fluidity are a maximum in the mixtures 

 of the other solvents with water in the 25 and 50 per cent mixtures, and in no 

 case are they a maximum in the mixtures of the alcohols and acetone with one 

 another. 



' Loc. cit. 



