Introduction to the study of organic chemistry : a text-book for students in the universitites and technical schools / by John Wade.

  • Wade, John.
Date:
1898
Catalogue details

Licence: Public Domain Mark

Credit: Introduction to the study of organic chemistry : a text-book for students in the universitites and technical schools / by John Wade. Source: Wellcome Collection.

    462/490 (page 440)
    APPENDIX II QUALITATIVE ANALYSIS The following scheme will be found useful in determining the nature of artificial mixtures of the organic compounds specified below with inorganic acids, bases, etc. (The tests for the individual compounds are given in Appendix I.). LIST OF SUBSTANCES I. Acids.—(Precipitable by calcium chloride ; precipitable or coloured by ferric chloride; precipitable by mineral acids) : — i. Calcium salts precipitable: oxalates (p. 423), white, immediate; tartrates (p. 425), white, on rubbing; citrates (p. 425), ivliite, on boiling with ammonia. ii. Ferric salts coloured, and precipitable in cold: benzoates (p. 432), buff, pidverulent; hippUrates (p. 432)” brown, flocculent; suc- cinates (p. 425), red, gelatinous. [Tartrates also precipitated from very concentrated solutions, and cyanides from slightly alkaline solutions.] iii. Ferric salts coloured and precipitable on boiling : acetates (p.41G), red solution, brown precipitate; formates (p. 418), same. iv. Ferric salts coloured and imperfectly precipitable : gallates (p. 434), blaclc; tannates (p.434), blade; ferrocyanides (p.428), dark blue. v. Ferric salts or compounds coloured and soluble: thiocyanates (p. 429), red; ferricyanides (p. 42S), greenisli-broum; sali- cylates (p. 434), violet; phenates (p. 431), violet. \i. Convertible into compound precipitable by ferric chloride : Simple cyanides (p. 428). vii. Insoluble in acids : uric acid (p. 428); benzoic and succinic acids; phenol (oil from concentrated solution). II. Alkaloids and Amines.— (Precipitable by sodium carbonate or caustic soda) :— i. Solid precipitate: strychnine (p. 438); quinine (p. 438); morphine (p. 438). ii. Oil (from concentrated solution): aniline (p. 431). III. Amide.—Soluble in water; hydrolysable by concentrated caustic soda; urea. IV. Carbohydrates. — (Precipitable only by special agents; non- volatile :—• i. Soluble in cold water: cane-sugar (p. 425), readily; milk-sugar (p. 426), with difficulty ; glucose (p. 425), readily. ii. Soluble only in hot u-ater : starch (p. 426). V. Alcohols and Derivatives.—(Distillable alone, or u-ith alkalies or acids; and precipitable only by special agents) :— i. Stable to alkalies: alcohol (p. 414), readily volatile; glycerol (p. 424), difficultly volatile; [acetic and formic acids]. ii. Decomposed by alkalies: chloral (p. 423), immediately ; chloroform (p. 422), ii’ith cone, alcoholic alkali; [hydrocyanic acid], 410