OCR Text |
Show Nitric Acid and Tin. In a paper read before the London Chemical society by C. H. Walker on the action of nitric acid on tin, some of the prevalent ideas on that subject are shown to be singularly erroneous. Among these is the general supposition that metallic tin dissolves in nitric acid with the production of both a stannous and stannic salt, according to the conditions condi-tions of temperature and concentration of the acid In these later experiments made to determine the amounts of stannous salts formed under various conditions con-ditions of temperature, concentration of acid and mass of tin treated it is shown that with dilute acids the increase of temperature has but little effect, but with more concentrated acids the effect is more marked, for the alteration of a few more degrees will reduce the amount of stannous salt to nothing; while increase in-crease of concentration, other things being be-ing equal, decreases the proportion of stannous salt It is found that the yellowish yel-lowish white substance formed from concentrated con-centrated solutions is ahydrated stannic nitrate of varying composition, depending depend-ing on the time between production and analysis, also on the method of purification purifica-tion adopted for eliminating the nitric acid. New York Sun. |