Lessons in qualitative chemical analysis / by F. Beilstein ; translated from the fifth edition, with copious additions ... by Charles O. Curtman.

  • Beilstein, Friedrich Konrad, 1838-1906.
Date:
1883
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Licence: Public Domain Mark

Credit: Lessons in qualitative chemical analysis / by F. Beilstein ; translated from the fifth edition, with copious additions ... by Charles O. Curtman. Source: Wellcome Collection.

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    taste, of specific gravity 0.82. It boils at 78° C. and is readily inflammable, burning with a blueish, non-luminous flame. It mixes with water in all proportions, tt dissolves many sub- stances, and forms, with some, definite compounds called alco- holates. Absolute alcohol has spec. grav. 0.7937, and boils at 73.4 C. 1. In a testtube mix about 1 C.C. of solution of KgCrgO? with one fourth the quantity of H_>S04 and dilute with 2 or 3 C.C. of water. Now add 1 C.C. of alcohol, mix and heat gently. The liquid will heroine green from the formation of chromic alum while aldehyde C2H:;OH will volatilize, easily recognized by its odor. 3C2H5OH K2Cr207+4H2S04=3C2H30H K,S04 .('r>(S04 7H.0 2. Mix in a testtube about 1. C.C. each of H2S04and C2H5OH beat to boiling and again add the same quantity of alcohol on heating, ether, (C2H.-,)20, is formed, whose odor is easily de- tected. The reaction occurs in two stages. First acid ethyl sulphate (ethyl-sulphuric acid), C2H5.H.SO4, is formed, and then with more alcohol, ethjiic ether and sulphuric acid. a. (,H>OH+H2S04=C2H .H.S04 H20 l). C2H „H.SO4+12H ,.OH= (CaHe) 20-fH2S04. 3. Mix in a testtube equal volumes (about 1 C.C. each) of alcohol, sulphuric acid and a saturated solution (or a crystal) of sodium acetate. Apply heat and there will he formed ethyl acetate (acetic ether), C2H5.C2H.3O2j whose fruity odor will lie easily recognized. Acid ethyl sulphate is first formed ami t Iii-decomposes with sodium acetate into acid sodium Sulphate and ethyl acetate. C,H H.S04 >aC-H 02=(,H , (2Hy02+NaHSt)4 4. Into 2 C.C. alcohol put a small crystal of iodine and dissolve it at a gentle heat. Now add drop by drop a solu- tion of KOH, until the brown color of the solution disappears. At <mce a copious yellow precipitate of Iodoform, CHLs, falls down, well characterized by its odor, while potassium iodide and potassium formate are in solution. C.H.-..0H bKOH fls=( HI , CH02K+5KI+5H20. 5. To a small quantity of molybdic acid, dissolved in con- centrated H>S04 and heated, add cautiously in a testtube a