Page:Text-book of Electrochemistry.djvu/72

 V.

��LOWERING OF THE FREEZING POINT.

��Methyl alcohol Ethyl alcohol Glycerol. . Cane sugar. Formic acid. Phenol. . . Acetic acid. Butyric acid. Ether. . . Ammonia. . Aniline. . Oxalic acid.

��Solutions ix Water.

(Calculated Molecular Lowering, 18'6.)

. . . . 17-3 ] Hydrochloric acid.

.... 17-3 Nitric acid. ..

. . . . 17*1 Sulphuric acid. .

. . . . 18'5 Potassium hydroxide

. . . . 19*3 Sodium hydroxide.

. . . . 15*5 Potassium chloride.

. . . . 19*0 Sodium chloride

. . . . 18*7 Calcium chloride.

. . . . 16*6 Barium chloride

. . . . 19*9 Potassium nitrate.

. . . . 15'3 Magnesium sulphate

. . . . 2*2-9 ' Copper sulphate. .

��Solutions in* Benzene. (Calculated Molecular Lowering, 53.)

��From the results given, it is evident that in the majority of cases the experimental result agrees with the theoretical. There are, however, a number of exceptions. In benzene solution many substances (alcohols, phenol, and organic acids) give smaller values for the molecular lowering than would be expected; thus, e.g., a gram-molecule of methyl alcohol (CHgOH = 32) only exerts about half its normal action.

This deviation is easily explained by assuming that a gram-molecule of methyl alcohol in benzene solution weighs 64 grams, or, in other words, the chemical formula for this alcohol in benzene solution is (CH80H)2; the molecular lowering is then calculated to be 506. Other deviations between experimental and theoretical results can in most

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