Practical organic chemistry / by Julius B. Cohen.

  • Cohen, Julius B. (Julius Berend), 1859-1935.
Date:
1908
Catalogue details

Licence: Public Domain Mark

Credit: Practical organic chemistry / by Julius B. Cohen. Source: Wellcome Collection.

    357/380 (page 337)
    Adds.—A free acid may be at once identified by its solubility in a solution of sodium carbonate and by being reprecipitated by concentrated hydrochloric acid. If a metal has been dis¬ covered in the preliminary examination, a careful examination must be made for an organic acid. As the substance is insoluble in water the metal will probably not be an alkali metal. Boil the substance with sodium carbonate solution. The sodium salt of the acid passes into solution and the metallic carbonate is precipitated. Filter ; boil the filtrate with a slight excess of nitric acid, add excess of ammonia and boil until neutral, tests may then be applied in order to identify one of the common acids and the m.p. determined ; but beyond this it is impossible to carry the investigation in a limited time. Insoluble Solids. (Containing C and H, or C, H, and O.) Hydrocarbons— Paraffin wax .... Naphthalene (p. 216) Anthracene (p. 225) Phenanthrene . . . Stilbene ... A Icohols— Cetyl Alcohol Menthol . . . A Idehydes— Vanillin. Piperonal . Ketones— Benzophenone . . . Benzil (p. 202) .... Benzoin (p. 203) . . . Camphor. Quinones— Benzoquinone (p. 192) a-Naphthaquinone . . P- Anthraquinone (p. 225) Phenanthraquinone A a ids— Palmitic (p. 104) . . . Stearic. Benzoic (p. 199) . . . £?-Hydroxybenzoic (p. 190) m- (p. 201) A 5 > Melting- Melting- point. point. A cids—(con tinned ) 45—60 Anisic. 184 80 0-Toluic . .. 102 217 »*- >, . no 99 P- „ (P- no) - • ■ • 179 125 Phenyl acetic. 76 0-Phthalio (p. 217) • - . 213 m- ,, (isophthalic subl. 5o p- ,, (terephthalic) > > 42 (P- 171) A nhydrides— 81 Benzoic. 42 37 Phthalic (p. 218) . . . . 128 Phenols— 48 95 137 i75 tf-Cresol . P- 0 (P- 164) .... 3i 36 Thymol. a-Naphthol. 44 95 A ,, (p- 219) . . 1 22 116 Esters— | I 2 ^ Methyl oxalate (p. 101) . 54 115—120 Cetyl palmitate (Sper- decomp. 285 205 maceti). Myricyl palmitate (Bees 53 wax). 62—65 Glyceryl 'tripalmitate (Palmitin) (p. 104) . 62 62 Glyceryl tristearate 69 (Stearin). 71 122 Phenyl benzoate .... 69 155 ,, salicylate . . . 43 200 Benzyl benzoate .... 21 210 ,, salicylate .... — COHEN’S ADV. P. O. C.