Patten—Solutions of Hydrochloric Acid in Solvents. 337 
H. F. == Heat of formation of anhydrous chlorides for 
chemical equivalents, taken from Thomsen. * 1 
\/B = Bllack coating removed upon running in HC1 gas. 
DISCUSSION. 
The results given in Table I show that solutions of hydro¬ 
chloric acid which are good insulators will in some cases act 
vigorously upon metals, and even permit the deposition of one 
metal upon another. Further investigation would in all like¬ 
lihood show that for each solvent there exists a definite concen¬ 
tration of HOI for which the action upon the metal is a maxi¬ 
mum. That this concentration would be the same for all metals 
is unlikely. The factors which determine whether or not action 
will take place 1 * * * * * * at the temperature:, pressure, and concentration 
studied are. the metal and the solvent. 
The conductivity of these solutions, slight as it is, gives no 
basis for predicting action upon the metals. As an instance 
of this, compare the action of the ethyl chloride solution and 
of the benzene solution with that of the tin tetrachloride solu¬ 
tion and of the silicon tetrachloride solution, taking into con¬ 
sideration the conductivity of these solutions as given under the 
detailed description of each solvent’s action. 
1 Thermochemische Untersuchungen, 3, 503-522. 
1 The conductivity of 0.1 N. HOI in water is 3,250X10~ 9 * * * . In the first 
chloroform experiment where the conductivity was greatest (save for the 
arsenic trichloride and for the thionyl chloride which solvents themselves 
exhibit a slight conductivity), 0.00025 ampere was obtained with 120 volts 
across 1mm. This gives for the conductivity of this solution of HC1 in 
chloroform 8,700X10— 13 approximately. If 120 volts were kept on this solu¬ 
tion for 10 hours, according to Faraday’s law, we should get 2.06 cc. of 
hydrogen. A 0.1 n. HCi solution in water would give under the same 
conditions 7,700 cc. of hydrogen, assuming no counter e. m. f., since the 
aqueous solution has a conductivity 3,750 times that of the chloroform 
solution. If now the action of the chloroform solution of HCI upon zinc 
were in proportion to its conductivity, we should expect hydrogen to be 
evolved upon the zinc 3,750 times slower than in 0.1 n. HCI in water. 
The fact is, the aqueous solution of HCI acts slower than the chloroform 
solution. But this chloroform solution was not dried to my entire satis¬ 
faction. The conductivity of the fourth chloroform solution was 34 of 
that given above. In this case hydrogen should be evolved 30,000 times 
slower in the chloroform than in the aqueous solution of HCI, speaking in 
round numbers. (Compare L. Kahlenberg, J. Phys. Chem. 6, 1, 1902.) 
Approximately the same figures and reasoning apply to the other sol¬ 
vents in which zinc or other metal was acted upon. The so-called period 
of induction appears to be of slight duration in these nonaqueous solu 
22 
