CARBON COMPOUNDS A SCHEME FOR THE DETECTION OF THE MORE COMMON CLASSES OF CARBON COMPOUNDS BY FRANK E. WESTON B.Sc. LONDON (FIRST CLASS HONOURS), F.C.S. LECTURER IN CHEMISTRY AT THE POLYTECHNIC, REGENT STREET, W. LONGMANS, GREEN, AND CO. 39 PATERNOSTER ROW, LONDON NEW YORK AND BOMBAY 1994 All rights reserved A^ C^lEBAl PREFACE THE lack of any systematic scheme for the identification of carbon compounds suitable for students preparing for the Final B.Sc. Examination of London and Honours Chemistry Exami- nation of the Board of Education, led the Author to draw up the present notes primarily for the use of his own students at the Polytechnic Institute, Regent Street, W. This scheme, which has grown to its present form as the result of several years' experience, has been found so useful to his own and other students, that the Author ventures to offer it to a wider public. The scheme enables a student to assign a carbon compound to its class, and, in many cases, to identify the body completely. The reactions of the com- monest substances are omitted, since they are to be found in the usual analytical organic text-books. POLYTECHNIC INSTITUTE, REGENT STREET, W., September, 1904. CONTENTS I.-V. Preliminary Observations 1-8 VI. C and H only present 9 VII. C, H, and Halogen present 12 VIII. C, H, O, and Halogen present 13 1. Substituted Acids 13 2. Acid Halides 14 3. Chloral and Chloral Hydrate 14 IX. C, H, and O present 15 1. Acids or Salts 15 (A) Saturated Acids 15 (B) Unsaturated Acids 16 (c) Hydroxy Acids 16 2. Phenols 18 3. Aldehydes and Ketones 20 4. Quinones 23 5. Phenol Alcohols and Phenol Aldehydes 23 6. Alcohols 24 7. Ethers . 24 8. Carbohydrates 24 9. Esters and Glucosides 25 X. C, H, and N present 27 3. Amines 28 3#. Diamines 29 4. Hydrazines 30 5. Alkaloids 31 6. Pyridine and Quinoline 31 7. Pyrrol and Alkyl 31 Vlll XI. C, H, N, and O present . 32 1. Amides 32 2. Amino-acids 33 3. Ureas 34 4. Ureides and Uric Acid 34 5. Isocyanates 36 6. Anilides 36 7. Esters of Nitrous and Nitric Acids 3^ 8. Nitro-compounds 37 9. Hydrazones 39 10. Osazones 40 11. Oximes 40 12. Azo-compounds 41 13. Alkaloids 41 XII. C, H, and S present 42 1. Mercaptans 42 2. Thio-ethers 43 3. Thiophenes 44 XIII. C, H, S, and O present 44 1. Sulphonic Acids 44 2. Alkyl Sulphates 44 XIV. C, H, S, and N present 45 1. Mustard Oils 45 2. Thio-ureas ' 46 3. Thiocyanates 46 XV. C, H, S, O, and N, or Halogen present 47 1. Amino-sulphonic Acids 47 2. Sulphonamides 47 3. Chloro-sulphonic Acids 48 XVI: Special reactions 48 SOLUBILITY OF CARBON COMPOUNDS 50-56 CARBON COMPOUNDS PRELIMINARY OBSERVATIONS I. Note carefully the obvious properties of substance, and determine m.p. or b.p. of it to ascertain if a single substance. Silowski's method of determining b.p. (see Fig. i). Prepare a capillary tube 3 cms. x I mm. with a constriction i cm. from one end. Place this in a small test-tube 5 cms. X 0*5 cm. with enough of the liquid to cover the shorter tube (A). Fasten this test-tube to a thermometer so that liquid in it is next to the bulb of the thermometer. Fix up the thermometer to dip into heating bath water if b.p. below 100 ; cone. H 2 SO 4 if above 100 C. and up to 200 C. On heating the bath, bubbles of gas will be seen to escape from lower open end of capillary slowly and irregularly, but when the liquid under examination attains the temperature of its b.p., a con- tinuous and regular succession of bubbles of gas will be obtained. Two or three observations should be made, but the small capillary should be taken out of the test-tube and replaced between two successive observations. II. Test very carefully for the elements N, Cl, Br, I, P, and S. (H should also be tested for, since CC1 4 contains none.) Oxygen cannot be tested for by any direct test. Its presence or absence will be indicated indirectly by some of the follow- ing observations : (a) Sodium reaction for delecting A 7 , S, and halogens. Prepare a hard glass test-tube 10 cms. x i cm., and support B it vertically from a piece of asbestos cardboard, 5x5 cms., resting on the ring of a retort stand (Fig. 2). Drop a piece of clean Na into 'the test-tube, and carefully heat it till it melts and begins to vaporize ; then drop into the test-tube about o'l gram of the substance, so that it falls directly on to the Na if a liquid, use a dropping-tube, and allow to fall drop by drop without touching sides of tube. Continue to heat the tube strongly till all apparent change Asbestos FIG. I. FIG. 2. is over. Allow tube to cool, and then add I to 2 c.c. of alcohol to dissolve excess of Na. When effervescence due to Na is over, add 10 c.c. of boiling water, boil 2 or 3 minutes, filter ; repeat with 10 c.c. more boiling water, filter, and collect with first filtrate. Examine filtrate as below (i.) To 10 c.c. add 5 c.c. of saturated solution of FeSO 4 , and few drops of NaOH soln. ; well boil ; add 2 or 3 drops of FeCl 3 , and make solution acid by care- fully adding cone. HC1. A blue solution or pre- cipitate shows formation of Prussian blue, and hence presence of a cyanide, and therefore presence of N in original substance. (N.B. If a greenish solution, or greenish-blue solution, is obtained, repeat ignition with Na, taking care that substance actually comes in contact with melted Na, and is well heated.) (ii.) Acidify 5 c.c. of nitrate with HNO 3 , and well boil (to expel HCN if present), and add AgNO 3 soln. ; a curdy white or whitish-yellow ppt. = AgCl, AgBr, or Agl. By usual tests ascertain which. Hence presence of Cl, Br, or I. (iii.) To 2 c.c. of nitrate add a freshly prepared solution of sodium nitro-prusside. A violet coloration shows presence of a sulphide, and hence S in original. Confirm by soln. of (CH 3 COO) 2 Pb in original. (iv.) To 2 c.c. of nitrate neutralized by HC1 add a few drops of FeCl 3 soln. A deep red coloration dis- charged by a soln. of HgCl 2 shows presence of a sulphocyanide, and hence of S and N in original. (V) Test for P. Melt a mixture of i gram K 2 CO 3 and i gram KNO 3 in a porcelain crucible; carefully drop in o'i to 0*2 gram of substance, and continue heating till effervescence ceases. Boil with 10 c.c. water, filter, acidify with cone. HNO 3 drop by drop, and test this solution for H 3 PO 4 by (NH 4 ) 2 MoO 4 . NOTE. AgNO 3 gives a white ppt. of AgCNS from HNO 3 solutions of sulphocyanides, hence if latter present chlorides must be confirmed in (a) (i.) by digesting ppt. with very dilute AmOH, filtering and acidifying filtrate with HNO 3 , when white ppt. = AgCl. III. Burn a little of the* substance on a roll of fine copper gauze (i sq. cm. of gauze rolled upon the end of a stout piece of wire). Aromatic compounds, hydrocarbons, unsaturated fatty compounds, fatty compounds containing more than 4 C atoms, produce soot. IV. Ignite a portion (if solid) on Pt foil, and test residue, if any, for carbonate, sulphate, sulphite, oxide, or metal (i.) Presence of a salt, (ii.) metallic derivative, viz. (a) Bisulphite of an aldehyde, or ketone. (b) Amido-metallic deriv. (c) Mercaptan. (d) Sulphonate, etc. (e) Nitro-metallic compd., etc. NOTE. Carefully observe odour in III. and IV. V. Try action of following on the substance : 1. WATER. If soluble, test soln. with litmus (see Table of Solubilities). If solution obtained, to it add soln. of KOH till alkaline ; a ppt. may be (i.) Metallic hydrate. (ii.) An organic base liberated from a salt, e.g. amine, alkaloid, etc. Acid halides evolve halogen acids (aromatic may require warming). 2. COLD KQH SOLN. (i.) NH 3 evolved from ammonium salts and detected on warming. (ii.) Amines liberated from their salts and detected by smell and alkalinity more so on warming. (iii.) Acids, phenols (also halogen and nitro derivatives), and most amides dissolve (sulphonamides dis- solve). (iv.) Some esters may dissolve more easily on heating. 3. COLD CONC. H 2 SO 4 . (i.) Saturated and aromatic hydrocarbons and their halogen derivatives insoluble. 5 (ii.) All other substances dissolve or are destroyed, excepting a few acids and N compounds. (iii.) Deep red coloration indicates certain glucosides, e.g. salicine, amygdalin, etc. yi. HOT CONG. H 2 SO 4 . Gently warm about 0-2 gram with i c.c. of cone. H 2 SO 4 . (i.) Blackening with effervescence (a) Carbohydrates and certain glucosides. (b} Alkaloids. (c) Certain higher oxyacids. (ii.) Blackening without effervescence (a) Certain poly-phenols. (b) phenol acids. 4. SODA LIME. Intimately mix 0*2 gram substance with 5 grams of powdered soda-lime ; place mixture in hard glass test-tube, and then 2 grams of coarsely grained soda-lime ; fit cork, and short right-angled tube. Strongly heat coarse soda-lime, and then the mixture (Fig. 3). (i.) NH 3 gas or ammoniacal vapours evolved (smell and litmus paper) (a) Ammonium salts. (b) Ammonium derivatives amines, amides ; ureas, ureides ; cyanides ; alkaloids, etc. (ii.) Inflammable gas evolved (a) H from formates, oxalates. (b) Hydrocarbons from acids or salts (CeH 6 from all aromatic acids with COOH group attached to benzene nucleus). (iii.) Phenols, (a) Oxy-aromatic acids or salts. (iv.) Smell of burnt sugar (a] Carbohydrates. (b) Glucosides. (c) Certain higher acids citric, tartaric, malic, tannic, gallic. 5. Na 2 CO 3 SOLN. Add OT to o'2 gram of substance to 10 c.c. of io/ Na 2 CO 3 soln.- (i.) Acids dissolve, but monohydricphenols insoluble, (ii.) Chlorophenols and nitrophenols dissolve, (iii.) Polyhydric phenols dissolve. FIG. 3. 6. METALLIC Na. Dissolve substance (or suspend) in anhydrous alcohol free ether, and add a clean thin slice of Na i X 0*5 cm. The apparatus shown in Fig. 4 will be found useful for carrying out this test. a is a small test-tube 7*5 cms. x i cm., into which the ethereal soln. and Na is placed. b and c are test-tubes 12*5 X 2*5 cms. ; b is filled with water. The connecting tubes are made of small-bore tubing. The gas evolved in a is collected in b, and water expelled in c. When action is over, the water in b and c can be levelled, and tube a disconnected. The gas in b can then be collected in test-tubes over a basin of water by pouring water into c (Fig. 5). FIG. 4. FIG. 5. (i.) H is evolved from : Compounds containing OH group, aldehydes, ketones, esters, amides, mer- captans, and hydrazines. (ii.) Hydrocarbons evolved from halides of the lower hydrocarbons. If H evolved, or if OH group suspected, but no H evolved, mix about O'l gram of substance in a dry test-tube with 0*2 to 0*3 gram PCls (if no action, gently warm). HCl gas will be evolved from compounds containing (a) OH group, viz. acids, alcohols, phenols, etc. R.CONH 2 + PC1 5 = R.CC1 2 NH 2 + POC1 3 ] (b) Amides R.CC1 2 NH 2 = R.CC1 = NH + HCl RCC1 = NH = R.CN + HCl. 7. Br. IN CC1 4 . Dissolve substance in CC1 4 , or in some solvent having no action on Br, and add to it drop by drop a soln. of Br in CCl* (i.) Decolorized instantly without evolution of HBr shows double or treble linking. (ii.) Decolorized with evolution of HBr shows sub- stitution. NOTE. (a) Phenols, amines, aldehydes, and ketones de- colorize instantly. (b) Some amines do so without evolution of HBr. ^(c) A ppt. may be obtained on adding Br. This may be due to (a) Certain mono-, di-, and trihydric phenols. (|3) oxy-aromatic acids and aromatic amines, (y) Certain alkaloids. N.B. Br water may be added to a water soln. of the sub- stance to see if decolorization takes place, but the evolution of HBr will not be observed owing to its solubility in water. 8. KMnO 4 SOLN. To cri gram substance in 5 c.c. of 5% soln. of Na 2 CO 3 add drop by drop a i/ soln. KMnOi. (i.) Unsaturated bodies decolorize it. (ii.) Saturated do not. EXCEPTIONS. Following bodies are oxidized, and hence decolorize it: Formic acid, malonic ether, phenols, oxybenzoic acids, aldehyde, aldehyde bisulphite, acetone, benzaldehyde, acetophenone, glycerine, and some sugars. The further examination of the substance will depend upon (i) The elements found in the substance. (2) The solubility of it in water, KOH soln., and Na 2 CO 3 soln. (3) The remaining properties discovered by preceding tests. The remaining tests are grouped under the headings of elements found. If C and H only have been detected, and the substance is soluble in water, it may be taken for granted that O is present, since all hydrocarbons are insoluble in water. Similarly, presence of C, H, and a halogen easily soluble in water, indicates presence of O. If C and H only detected and insoluble in water, then not only should C and H compds. be tested for, but also insoluble C, H, and O compds. VI. CABBON AND HYDROGEN ONLY PRESENT. Tests V. 3, 7, and 8 will have detected saturated or un- saturated body. To further differentiate 1. Carefully mix 0*5 c.c. or ex 5 gram of substance with 5 c.c. fuming H 2 SO 4 , stand for 5 minutes, carefully pour into 20 c.c. of cold water, and allow to stand. If entirely dissolved most probably aromatic. C 6 H 6 + H 2 S0 4 = C 6 H 5 S0 3 H + H 2 O 2. Repeat i, using fuming HNO 3 instead of H 2 SC>4 (take very great care). Aromatic form insoluble nitro-com- pounds which can be separated, washed, dried, and tested for N. C 6 H 6 + HN0 3 = C 6 H 6 NO a + H 2 O 3. To detect triple bond, carefully mix substance with ammoniacal Cu 2 Cl 2 soln. ; when coloured, insoluble body will be produced. C 2 H 2 4- Cu 2 Cl 2 = C 2 Cu 2 -f 2HCI 4. To distinguish between various benzene hydrocarbons : heat i to 2 grams of substance under reflux with either dil. HNO 3 or glacial acetic solution of chromic acid, cool and filter. [For oxidation use the following : ^ (i) HNO 3 i vol. acid to 3 vols. of water (requires long time). (2) CrO 3 2 parts K 2 Cr 2 O7, 3 parts cone. H 2 SO 4 , and 2 to 3 parts H 2 O.] 10 (1) For heating small quantities under a reflux, the apparatus depicted in the diagram (Fig. 6) will be found to meet all the cases occurring in this scheme. (2) By having another cork fitted with an adapter, the tubing 4-C771S FIG. 7. FIG. 6. FIG. 8. apparatus can readily be charged for distillation (see Fig. 7)- (3) In some experiments with reflux, gases will be evolved ; these may be collected by fitting a small delivery tube to condenser, and collecting in a test-tube over water in an evaporating basin (see Fig. 8). II Test residue for (i.) Benzole acid : from monosubstituted benzene. (ii.) Phthalic ado's : (a) Ortho from o. disubstituted benzenes or naph- thalene (with dilute HNO 3 ) ; sol. in hot water, alcohol, and ether. BaCl 2 gives a white ppt. to soln. of acid in NH 4 OH. (b) Iso from m. disubstituted benzenes; BaCl2 gives no ppt. to soln. of acid in NH 4 OH. (c) Tere from p. disubstituted benzenes ; almost insoluble in H 2 O, alcohol, and ether ; BaCl 2 gives white ppt. with soln. of acid in NH 4 OH. (iii.) Anthraquinone from anthracene. (iv.) Naphthaquinone from naphthalene (acetic acid soln. of CrO 3 ). NOTE. Solns. of naphthalene, anthracene, and phenan- threne in benzene mixed with soln. of picric acid deposit yellow, red, and yellow crystalline derivatives respectively on evaporation. The following are the more important aromatic hydrocarbons with their chief characteristics : Benzene, C 6 H 6 , b.p. 80-5. Toluene, C 7 H 8 , b.p. 110-3. Yields C 6 H 5 COOH with either dil. HNO 3 or Cr0 3 . o-Xylene, C 8 H 10 . Yields o. C G H 4 (COOH) 2 with alk. KMnO 4 only. . m-Xylene, C 8 H 10J b.p. 137. Yields iso C 6 H 4 (COOH) 2 with alk KMnO 4 , and with dil. HNO 3 on long heating. p-Xylene, C 8 H 10 , b.p. I36-I37. Yields tere C 6 H 4 (COOH) 2 with CrO 3 easily, and with dil. HNO 3 on long heating. Ethylbenzene, C 8 H 10 , b.p. 134.. Yields C e H 5 COOH with CrO 3 easily, and with dil. HNO 3 on long heating. Mesitylene, C 9 H 12 , b.p. 163. Yields trimesic acid C 6 H 3 (COOH) 3 easily (1.3-5) with dil. HNO 3 . Cumene, C 6 H 5 C 3 H 7 (iso), b.p. 153. Yields C 6 H 5 COOH with dil. HNO 3 or CrO 3 . 12 Cymene, C 6 H 4 <| ( ( _|],b.p. I75-I 7 6. Yields tere QH 4 (COOH) 2 by dil. HN0 3 orCr0 3 . 3 Hexamethyl benzene, C 6 (CH 3 ), ; , b.p. 264, m.p. 169. Yields C 6 (CO 2 H), ; by alk. KMnO 4 . Naphthalene, C 10 H 8 , m.p. 149. Yields C 6 H 4 (COOH) 2 with dil. HNO 3 . Phenanthrene, C 14 H 10 , m.p. 99. Yields C H H 8 O 2 (Phenanthraquinone) by Cr0 3 , m.p. 198. Anthracene, C 14 H 10 , m.p. 213. Yields C 14 H S O 2 (Anthraquinone) by CrO 3 , m.p. 277. Styrolene, C 6 H,CH = CH 2 , b.p. 144. Yields C 6 H 5 CO 2 H with CrO 3 . Phenylacetylene, C 6 H 5 C = CH, b.p. 139. Yields C 6 H 5 CO 2 H with CrO 3 ; yields (C 8 H 5 ) 2 Cu 2 bright yellow and (C 8 H 5 ) 2 Ag 2 white. Stilbene, C 6 H 5 CH = CHC 6 H 5 , m.p. 120. Yields C 6 H 5 CO 2 H with CrO 3 or KMnO 4 . VII. CARBON, HYDROGEN, AND HALOGEN PRESENT, Note odour carefully. I. Digest i to 2 grams with 20 c.c. of alcoholic potash under reflux for 10 to 15 minutes. (a) Observe whether any gas evolved, viz. C2H 4 ,C 3 H6, C 4 H 8 , or C 2 H 2 . (b) Dilute with water, f^r, acidify with HNO 3 , and add AgNO 3 : ppt. = AgCl, AgBr, or Agl (identify which). This reaction given by fatty derivative or aromatic with halogen in side chain. Aromatic halide in side chain have irritating odour. C 6 H 5 .CH 2 C1, b.p. 176. Yields benzaldehyde when boiled with H 2 O and Pb(NO 3 ) 2 . CH 5 CHC1 2 , b.p. 206. Yields benzaldehyde when boiled with H 2 O and Pb(NO s ) 2 easily. "-!,- . ' V -' (c) Test portion of resitfue 'in flask for a Formate : shows presence of CHC1 3 or CHBr 3 . Test specially for CHC1 3 , CHBr 3 , CHI 3 , and CC1 4 . 13 CHC1 3 , b.p. 6 CHBr 3 , b.p. 151. CHI 3 , m.p. 119. CC1 4 , b.p. 767. CC1 4 . This can be identified as follows : (1) B.P. 767- (2) Warmed with ale. KOH and few drops C G H 5 NH 2 gives odour of carbylamine after a few minutes. (3) Treated with Zn and HC1 reduced to CHC1 3 , which gives carbylamine reaction at once. (4) Does not reduce Fehlmg's soln. ; CHC1 3 does on well boiling. 2. Allyl derivatives identified by leek-like odour and tests V. 6 and 7. C 3 H 5 C1, b.p. 46. C 3 H 5 Br, b.p.7o-7iC. C 3 H 5 I, b.p. 101 C. 3. Aromatic with halogen in nucleus produce nitro-deriva- tive easily, etc. VIII. CARBON, HYDROGEN, OXYGEN, AND A HALOGEN PRESENT. Indicates (a) Substituted Acids; (b) Acid Halides ; (c) Chloral and Chloral Hydrate. Tests V. I, 2, 5, and 6 will have indicated (a) and (b). i. SUBSTITUTED ACIDS. (i) Dissolve 0*5 to i gram in 50 c.c. N.NaOH soln., N and titrate excess of alkali with rH^SO^ using phenolphthalin as indicator. Calculate from quantity of alkali used by substituted acid the equivalent weight of the acid. 14 (2) Mix 0*5 gram of acid with 5 c.c. of water, and sufficient Na amalgam to make soln. alkaline when action over ; filter ; acidify filtrate with HC1 when organic acid is liberated from sodium salt. If acid insoluble, filter off; if soluble, extract with ether. Identify the acid as below (see " Detection of Acids "). In this reaction certain substituted acids are reduced to corre- sponding acids, viz. (i.) All substituted acetic acids ; (ii.) a dihalogen acids ; (iii.) o/3 dihalogen acids yield corresponding un- saturated acid. Commonest are : CH 2 Cl.CO 2 H,m.p. 62; CHC1 2 CO. 2 H, b.p. 190 (boiled with aqueous potash yields oxalic and acetic acid) ; CC1 3 CO 2 H, m.p. 52 (boiled with aq. KOH yields CHC1 3 and CO 2 ) ; CBr 3 CO 2 H, m.p. 135 ; C 6 H 4 .C1.COOH, o. m.p. 137; m. m.p. 153; p. m.p. 140; C 6 H 4 Br.COOH, o. m.p. 147; m. m.p. 155 ; p. m.p. 251. 2. ACID HALIDES. (1) The free acid is obtained by decomposing with water. Carefully add I c.c. of acid to 5 c.c. of water ; if no action, carefully heat ; if no action, add NaOH and heat, when the sodium salt will be formed. Separate as I (2). (2) To i c.c. of absolute alcohol carefully add the acid halide drop by drop till action ceases ; warm gently for 5 minutes, and pour into 10 c.c. of water. Separate the ester which settles in i ; wash with dilute Na 2 CO 3 , then water ; dehydrate 'with fused CaCl 2 , and determine b.p. (Note also odour of ester.) 3. If i and 2 absent, test specially for chloral CCla.CHO, b.p. 97, or chloral hydrate CC1 3 .C*y and CH 3 CO 2 H. Alk. salt solns. yellow with green fluorescence. C. HYDROXY ACIDS. (a) To a neutral solution add 2 or 3 drops of 10 / FeCl 3 soln. (a) Hydroxy acids produce a yellow coloration ; a-hydroxy acids a strong yellow colour. Hence test for following : Glycollic acid, m.p. 80. Lactic acid CrOa oxidizes it to acetic acid and COg. Malic acid, m.p. 100. (CaCl2 ppts. Ca salt on boiling from neutral solutions.) Tartaric acid, m.p. 167- 170. (CaCJ 2 ppts. Ca salt in cold from neutral solutions.) 17 Citric acid, m.p. 100 (crys.). (CaCl 2 ppts. Ca salt in boiling from neutral solutions.) Mandelic acid, m.p. 132*8. (]3) o-Hydroxy acids produce a violet coloration (volatile in water-vapour and soluble in CHC1 3 ). Test specially for salicylic acid, m.p. 155. (y) o-Dihydroxy m. acid (e.g. protocatechuic acid, C 6 H 3 (OH) 2 .COOH(i.2 4), or any of its deri- vatives) produce a blue colour after addition of a few drops of dilute NaOH. () Trihydroxy monobasic acids a bluish-black . or dark blue ppt. given by certain of these, e.g. Gallic acid, m.p. 220 with decomposition. Tannic acid. (U) If no colour produced with FeCl 3 , test specially for (a) m-Hydroxy acids, which give a reddish-brown when heated with cone. H^SO*. (]3) p-Hydroxy acids boiled with cone. HC1 yield a phenol and CO* All hydroxy acids (i.) When acted upon by acid chloride, yield esters in which acid residue enters the alcohol OH group. (ii.) When acted upon by a mixture of cone. HNO 3 and H 2 SO 4 have the H of the alcoholic OH group replaced by NO 2 group. These two reactions can be applied to prepare the alcohol esters and nitrates, and hence used as a means of identifying acid. (2) If the acid cannot be identified by any of the above reactions the following experiments should be carried out: (a) Mix 2 to 3 grams of the acid with 10 c.c. of absolute alcohol, and conduct into the mixture dry HC1 gas till no more absorption takes place. Heat C 18 this mixture under reflux for 30 minutes, cool and separate ester by diluting with large bulk of water, when it will settle out ; if a portion does not separate the ester by this treatment, then it must be separated by distillation. Determine b.p. (b) The eqt. wt. of the acid should be determined as in VIII. I. (c) Prepare the Ag or Pb salt, and determine mol. wt. 2. PHENOLS. The phenol may be identified by forming benzoyl ester with CeH^COCl (or one of its deriva- tives), separating and det. m.p. or b.p. (Schotten- Baumann Reaction). 1 (1) (i.) Monohydric Phenols. Those of low molecular weight are slightly soluble, but solubility decreases with increase of molecular weight. Sol. in NaOH soln. (ii.) Dihydric Phenols. More soluble ; soluble in Na 2 COa soln. (iii.) Trihydric Phenols. More soluble still in Na 2 COa soln. (2) Carefully add 2 c.c. of CH 3 COC1 to i gram of a phenol ; warm if necessary, and then carefully pour into 10 c.c. of water; an oil will settle out due to the formation of an ester of acetic acid. It can be separated, dried, and b.p. detd. (20) Use C 6 H 5 COC1 instead of CH 3 COC1, followed by NaOH in excess, etc. (see IX. 2). (3) FeCl 3 soln. added to a solution of a phenol produces coloration discharged by HC1. (i.) Monohydric mostly violet to blue. (Thymol pro- duces no colour.) 1 Take from o'5 to I gram of substance in a test-tube with 5 c.c. H 3 O ; then add I c.c. C 6 H 5 COC1 and soln. of NaOH (i in 10) till soln. alkaline; well shake till smell of C 6 H 5 COC1 has disappeared. Then pour into large excess of water, when the benzoyl derivative will settle out. If it does not solidify at once, allow it to stand some minutes, when it will gradually crystallize. Separate it, well wash with water, dry, and determine m.p. 19 (ii.) Dihydric (ortho) green coloration. (iii.) (meta) violet. (iv.) Trihydric green, violet, blue to black. EXCEPTIONS. (a) Paradihydric phenols are oxidized to quinones, which settle out in golden yellow crystals. (b) a-Naphthol gives a white to violet ppt. of dinaph- thol ; ]3-, green to white. (c) Nitrophenols, meta, and para oxyacids do not produce any colour. (4) Heat in a small test-tube for i to 2 mins. to about 150 C. (do not char) 0*2 gram of a phenol with 0*2 gram of phthalic anhydride moistened with a drop or two of cone. H 2 SO 4 . Cool and treat fused mass with cold water, and then add NaOH soln. very gradually, till -no further change occurs. Coloured solutions will be obtained, some of which will fluoresce, especially the m. dihydric phenols. Phenol gives an intense red solution. Pyrocatechin gives an intense blue solution. Resorcin gives an intense yellowish-red soln. with green fluorescence (fluorescein). Pyrogallol gives an intense blue. (5) Add saturated Br water to 5 c.c. of a phenol soln. till soln. is yellow ; a white ppt. of a tribromphenol will settle out. (6) Liebermann's Reaction : To a pinch of a phenol add 5 or 6 drops of cone. H 2 SO4, and then a very small piece of KNO 2 ; a deep blue or green coloration is obtained. Pour into water ; it turns red, and on adding excess of alkali, blue or green. (All phenols do not give this reaction.) 20 The following are the more common phenols : (1) Phenol, C 6 H 5 OH, m.p. 43. /CH 3 (i) (2) Carvacrol, C 6 H 3 CH(CH 3 ) 2 (2), b.p. 236 C. "M>H (4) duces green coloration with alcoholic soln. /CH 3 (i) (3) Thymol, C 6 H 3 OH (3), m.p. 51-5. 10 c.c. of \CH(CH 3 ) 2 ( 4 ) aqueous soln. treated with i c.c. acetic acid and 2 c.c. H 2 SO 4 gives on warming red-violet coloration. (4) Pyrocatechol, C 6 H 4 (OH) 2 (1.2), m.p. 104. (5) Resorcin, C 6 H 4 (OH) 2 (1.3), m.p. 119. (6) Hydroquinone, C 6 H 4 (OH) 2 (i.4), m.p. 169. (7) Cresorcinol,C 6 H 3 < (0)2(4) , m.p. io4-io5. FeC) 3 to aq. soln. gives greenish-blue coloration. (8) Orcinol c e H <(QH) ? 5 )i m -P- IO 7- FeCl 3 to aq. soln. gives deep blue violet. To aq. soln. add KOH soln. and few drops of CHC1 3 , and then warm; a purple soln. turning fiery red is produced, which on diluting with water gives an intense fluorescence. (9) Pyrogallol, C 6 H 3 (OH) 3 (1.2.3), m.p. 131. (10) Phloroglucinol, C 6 H 3 (OH) 3 (1.3.5.), -P- 217. (i.) To aq. soln. add KNO 2 soln. and C G H 5 NH 2 .HNO 3 soln. a cinnabar-red ppt. of benzeneazophloroglucinol obtained. (ii.) Dip a pine shaving (matchwood) in HC1, and then into aq. soln. a deep red coloration. (11) a-Naphthol, C 10 H 7 OH, m.p. 99 (easily sol. in C 2 H 5 OH, (C 2 H 5 ) 2 O, CHC1 3 , or C 6 H 6 ). Soln. of bleaching powder to aq. soln. gives a deep violet coloration and then dark violet ppt. (12) -Naphthol, C 10 H 7 OH, m.p. 122. Bleaching powder a yellow coloration, disappearing on adding excess. Both naphthols give red-coloured azo dyes when coupled to diazotized C 6 H 5 NH 2 HC1. Both, when heated in strong aqueous alkali soln. with CHC1 3 to 50, give a Berlin blue colour, gradually changing through green to brown. 3. ALDEHYDES AND KETONES. Aldehydes and ketones are best liberated from their bisulphite derivatives by heating with a soln. of Na 2 CO 3 or K 2 CO 3 . 21 (1) TOLLEN'S REACTION. In a test-tube cleaned with hot NaOH and then distilled water, place 2 c.c. AgNO 3 soln., and then NH 4 OH soln. drop by drop till ppt. first formed is just redissolved. Then add I c.c. NaOH soln.; shake the mixture round the tube, and then allow 2 or 3 drops of an aldehyde solution to flow down the moistened surface. An immediate deposit of Ag is obtained (do not warm). (la) Repeat above expt. without NaOH, and warm if necessary. NOTE. This reaction is also given by other com- pounds, e.g. di- and trihydric phenols, and amido phenols, etc. (These reactions not given by ketones.) (2) CARO'S REACTION. Add 2 or 3 drops of an aldehyde soln. to 5 c.c. of Schiff's reagent (fuchsine solution which has been just decolorized by SO 2 ) ; the colour is restored. NOTE. Some ketones will react similarly if in large quantity and allowed to act for some time. (3) Add a small pinch of diazo-benzene-sulphonic acid to 5 c.c. of water, then a few drops of NaOH and a few drops of an aldehyde soln., and finally a small piece of Na amalgam (size of a pea) ; a red-violet colour is produced. Diazo-benzene-sulphonic acid C G H 4 < ^ 2 >O is prepared as follows : Dissolve 2 grams sulphanilic acid in smallest amount of Na 2 CO 3 soln. ; add I gram of KNO 2 dissolved in 5 c.c. of water. Pour this solution slowly into 10 c.c. of dilute H 2 SO 4 (i acid to 9 water), keeping the solutions well cooled. The diazo compound separates as a crys. solid on standing. 22 (4) Make 10 c.c. of a cold saturated soln. of sodium bisul- phite. To this add 2 to 3 c.c. of an aldehyde soln. (or i c.c. of free aldehyde) and well shake. A crystal- line solid settles out of aldehyde sulphite. Separate these crystals, wash with a little cold water. Then mix with some Na 2 CO 2 soln., and distil into a test-tube containing I c.c. of water ; prove that aldehyde is in distillate by (2). NOTE. Ketones produce similar crystalline com- pounds. (5) To 5 c.c. water add i c.c. C 6 H 5 NH.NH 2 , and then cone. HC1 drop by drop till dissolved ; to this add soln. of 2 grams CH 3 .COONa in 10 c.c. H 2 O : now add i c.c. of the aldehyde (or 5 to 10 c.c. of the soln.). Heat the mixture on a water-bath, when a hydrazone of the aldehyde will settle out after some time. If solid it can be crystallized from water, alcohol, or benzene, and its m.p. determined (see XL 9 for m.p. of few common ones). The hydrazones of lower fatty alde- hydes are oily liquids, and difficult to purify. + C 6 H 5 NH.NH 2 = RCH:N.NH.C 6 H 5 + H 2 O + C 6 H 5 NH.NH 2 = R.R'C:N.NH.C 6 H 5 + H 2 O (6) Warm 2 c.c. KOH soln. with i c.c. of aldehyde soln. ; yellow colour is produced and a resinous mass separates. (7) Aromatic aldehydes, when treated with alkalies as in (6), yield alkalies and acids, e.g. 2C 6 H 5 CHO + KOH = C 6 H 5 CH 2 OH + C 6 H 5 COOK To i c.c. of the aldehyde add 5 c.c. of 10% alcoholic soln. of potash ; allow to stand ; a solid settles out. Filter and wash ppt. with a little alcohol. Dissolve ppt. (K salt) in water 23 and acidify with HC1, when the free acid is pptd., and can be identified. The alcohol soln. contains an aromatic alcohol, which is left on carefully evaporating the alcohol off. (8) Aromatic aldehydes also yield condensation products with anilines ; viz. formation of malachite green from benzaldehyde. Heat I c.c. benzaldehyde and i c.c. dimethylaniline and I gram fused ZnCl 2 in crucible to ioo-no C. ; cool and transfer to basin and boil with water and a little HC1 ; to this add a little PbC>2 in cold, when green colour is obtained. The following are amongst the more common : Formaldehyde, H.CHO (in soln.). Acetaldehyde, CH 3 .CHO (in soln.). Acrolein, CH 2 = CH.CHO, b.p. 52. Crotonaldehyde, CH 3 CH = CH.CHO, b.p. 104. Benzaldehyde, C 6 H 5 CHO, b.p. 179. Cinnamicaldehyde, C 6 H 5 .CH : CH.CHO, b.p. 247. Acetone, (CH 3 ) 2 CO, b.p. 56-5 (idoform reaction). Acetophenone, C G H 5 CO.CH 3 , m.p. 26-5, b.p. 202. Benzophenone, C 6 H 5 CO.C 6 H 5 , m.p. 48-49. Benzoin, C G H 5 CH(OH).CO.C 6 H 5 , m.p. 134. Benzil, C 6 H 5 CO.CO.C 6 H 5 , m.p. 90. Furfurol, C 4 H 3 O.CHO, b.p. 162 (see Pentoses). 4. QuiNONES. Yellow (orange to red)crys. solids, peculiar odour, volatile either alone or in steam. SO 2 solution reduces them to colourless dihydroxy compounds. NOTE. Anthraquinone not reduced by SO 2 . Q Naphthaquinone ) n, ? } non-volatile and odourless. Phenanthraqumone ) 5. PHENOL ALCOHOLS AND PHENOL ALDEHYDES. These possess properties of phenols, alcohols, and aldehydes. The esters of these compounds are important. The commonest are Saligenin, C G H 4 b.p. 248. /OH (i) Protocatechuic aldehyde, C G H 3 OH (3), b.p. 150. FeCl 3 gives deep green to aq. soln. ^CHO (i) Vanillin, C G H 3 OCH 3 (3), m.p. 8o-8i. Fused with KOH \OH (4) /OH yields protocatechuic acid, C 6 H 3 OH , which gives \COOH green coloration with FeCl 3 soln. 6. -ALCOHOLS will have been indicated by V. 6, and solu- bility in water. (i.) Apply special tests for CH 3 OH, C 2 H 5 OH CgHuOH, and C 6 H 5 CH 2 OH, b.p. 206. (ii.) Form benzoyl ester with CeH^COCl, separate and det. m.p. or b.p. (see IX. 2). (iii.) Oxidize with chromic acid (see VI. 4) and examine products of oxidation, viz. aldehydes or ketones. 7. ETHERS. Indifferent bodies, and identified by b.p. 8. CARBOHYDRATES. Test V. 3 and 3^; will give indication (Molisch's reaction). To a small portion of substance add 5 c.c. H 2 O, 2 drops of 20 / alcoholic soln. of a-naphthol and 2 c.c. cone. H 2 SO 4 : a deep violet coloration is produced, discharged by KOH. If carbohydrate is present, test systematically for (i.) Glucoses, (a) Pentoses, (b) Hexoses. (ii.) Disaccharides. (iii.) Polysaccharides. To distinguish between pentoses and hexoses. Distil i to 25 2 grams of substance with 10 c.c. of water and 5 c.c. cone. HC1 ; collect 5 c.c. of distillate and divide into two portions. (1) Add few drops of aniline and cone. HC1 : a deep red coloration due to presence of furfurol C 4 H 3 O.CHO. (2) Carry out Molisch's reaction. The presence of furfurol indicates a pentose. The following are the more common : Glucose, m.p. I44-I46. Osazone yellow crys., m.p. 2O4-2O5. Galactose, m.p. i63-i64. Osazone yellow crys., m.p. 193- 194. Pentacetate with (CH 3 CO) 2 O, m.p. 142. Fructose, m.p. 95. Osazone yellow crys., m.p. 2O4-2O5. Cane-sugar, m.p. 160. No osazone. Hexabenzoate with C H 5 COC1, m.p. 109. Lactose, m.p. 203-5 to brown liquid. Osazone, yellow crys., m.p. 200. Maltose. Osazone, yellow crys., m.p. I9o-i9i. Arabinose, m.p. 100. Osazone, m.p. 158. Rhamnose, m.p. 93. Osazone, m.p. 180. Prepn. of Osazone. Dissolve i gram of the carbohydrate in 10 c.c. of water in a basin. Add 5 grams C 6 H 5 NH.NH 2 , and 5 c.c. glacial acetic acid. Place on beaker of boiling water. Yellow crys. will settle out in from 10 mins. to 15 mins. Filter, wash with water, dry, and det. m.p. 9. ESTERS AND GLUCOSIDES. Digest 2 grams or c.c. of substance with 50 c.c. of 10% KOH soln. under reflux till ester, etc., has disappeared ; distil over | of the liquid and proceed as follows : Distillate, test for alcohol by (a) oxidn. to aldehyde, etc. ; (b) with C 8 H 6 COC1, etc. Residue in flask, dilute with water and filter if neces- sary. Test one portion of solution for glucose ; if present = glucoside. If glucoside absent, test for acid obtained from the ester, which if insoluble in 26 water can be pptd. by acidifying with HC1, and then identified as in i. The eqt. of the ester can be determined by digesting i gram with 50 c.c. N.NaOH (alcoholic), and titrating N excess of NaOH after hydrolysis with H 2 SO4. If glucoside present, the following may be tested for : i. Salicine,m.p.2oiC. C 6 U 4 <^^ 5 ^. Bitter taste. (a) Cone. H 2 SO 4 produces a red coloration. () Take 0*15 gram KOH and 0*5 c.c. H 2 O in a crucible, and heat till KOH dissolved ; add 0*5 gram of sub- stance, and gently heat till mass just solidifies ; cool, boil with water, and filter. Test filtrate after neutra- lizing for salicylic acid by adding few drops of FeCl 3 soln. deep violet coloration. (c) When hydrolyzed by dil. H 2 SO 4 , products are glucose and saliretan a condensation product of salegenin which settles out as a whitish-yellow powder on cooling. Oxidizing this product (add K 2 Cr 2 O 7 soln., and cone. H 2 SO 4 to liquid after boiling with dil. H 2 SO 4 )and distilling over about 2 c.c. of the liquid salicylic aldehyde will be found in the distillate, which is recognized by its aromatic odour and deep violet coloration produced with FeCl 3 soln. 2. Populin, C 6 H 4 6 , m -P- l8 7- Sol. in water. 27 (a) FeCl 3 gives deep blue colour to its soln. (0) Hydrolyzed with dil. H 2 SO 4 yields C 6 H 4 (OH) 2 (1.4) and C fi H 19 O fi . Hence test for these. X. CARBON, HYDROGEN, AND NITROGEN PRESENT. Indicates Amines, Hydrazines, Alkaloids, Cyanides, and Isocyanides. Pyridine and Quinoline. Pyrrol group. To a little of the substance add dilute HC1 (i to 10). (i.) Immediately dissolves = amine, alkaloid or hydrazine, pyridine, and quinoline. (ii.) Insoluble or very slowly sol. = cyanide or iso- cyanide. [If substance is a salt of amine, etc., it will be soluble in water, and test V. i will have indicated.] A. INSOLUBLE IN DILUTE HC1. Ethereal smell = cyanide ; disgusting odour = isocyanide. 1. HEAT i to 2 c.c, under reflux with 20 c.c. cone. HC1 till substance completely decomposed. Make alkaline with NaOH soln. and heat, (i.) Alkaline vapours evolved may be (a) NH 3 from a cyanide ; (b) Amine from an isocyanide ; recognized as in X. 3 (i.) (a), (b) ; if latter, it may be collected in dil. HC1, the PtCl* salt formed and mol. wt. determined, (ii.) Test liquid remaining in flask for (a) Sodium formate = isocyanide ; (b) Sodium salt of other organic acicjs = cyanide. R_N = C -h 2H 2 O = RNH 2 + HCO 2 H R_C = N + 2H 2 O = R.CO.OH + NH 3 2. Mix i c.c. of substance with 10 c.c. of dil. HC1 (i to 3) and add Zn dust ; the cyanides are converted into 28 amines, which can be isolated and identified as in X. 3 (i.) (a), (b). (Na and absolute alcohol can be used instead of Zn, etc.) B. SOLUBLE IN DILUTE HC1. Proceed as follows : 3. AMINES. (i.) Mix o-i gram of substance with 3 drops CHC1 3 and 2 c.c. alcoholic potash and gently warm ; disgusting odour due to a carbylamine indi- cates a primary amine 1 (mono or di- ; fatty or aromatic). To distinguish between fatty and aromatic, dissolve o'l gram of substance in excess of dil. HC1 ; cool thoroughly and add a solution of KNO 2 or NaNO 2 till excess of free HNO 2 is obtained (place drop of diazolized soln. in a soln. of starch and KI). Divide into two portions (a) Heat one portion, N is evolved, and (a) An alcohol produced = fatty. (|3) A phenol = aromatic. (b) To other portion add a soln. of a or |3 nahpthol in NaOH, when an intensely coloured ppt. will be obtained if aromatic. (Mono- or p. di-amine.) (ii.) Secondary and tertiary. If primary absent, on adding NaNO 2 soln. to acid soln. of body a yellow ppt. or soln. is obtained of a nitroso- compound if amine is secondary or tertiary. This may be separated and confirmed by 1 Confirm primary amine by Hofmann's mustard-oil reaction : Digest o'l gram of substance with i c.c. CS 2 and i c.c. of HgCl 2 soln. ; a characteristic odour -is produced, due to formation of a mustard oil. CS p> I44 C ' (i.) KNO 2 and HC1 on warming yields salicylic acid, (ii.) Heated with soda-lime yields C 6 H 5 OH and NH 3 . (iii.) Heated with CaO yields C 6 H 5 NH 2 . (6) Hippuricacid,CH 2 ;NH.CO.C 6 H 5 . m p> ^ Digest 0*5 gram with 10 c.c. cone. HC1 under reflux for 15 minutes. Cool, filter off crystals of benzoic acid (test D 34 these), neutralize filtrate with NH 4 OH, boil off excess of NH 3 , and add CuSO 4 ; a deep blue colour due to copper glycocoll. ( 7 ) Betaine, CH/) 3 OH. (i.) Heated alone gives N(CH 3 ) 3 and odour of burnt sugar. (ii.) Fusion with KOH yields N(CH 3 ) 3 . (iii.) I in KI ppt. brown ppt. of periodide. 3. UREAS. (i.) Apply usual tests for urea (cone. HNOa gives best result [viz. to 2 c.c. of strong soln. in a watch-glass add 3 or 4 drops of cone. HNOa ; crystals of urea nitrate immediately settle out]. (ii.) Alkyl ureas, when digested with KOH, are decom- posed primarily into CO2 and amines, viz. CO 'NC 2 H 5 5 'H + 2KOH = 2C 2 H 5 NH 2 + K 2 C0 3 Hence test for carbonate in residue and for amine in distillate (if volatile) ; if non-volatile test for amine in residue. 4. UREIDES. These, when heated with KOH, are decomposed into urea and an acid [the urea is further decom- posed as in 3 (ii.)], hence test for a carbonate and the K salt of the acid produced by hy- drolysis, e.g. .NH.CO Parabanic acid, CO | + 2H 2 O .NH.CO Oxaluric acid, CO -NH.CO.CO 2 H .lNrl = CO ;a + (CO.OH) 2 .CO 2 H + HaQ = co > + (co.OH) 2 35 Malonyl urea, CO ''rn' CH * + 2 (Barbituric acid) = CO ' 2 -I- CH 2 (CO.OH) 2 Mesoxalyl urea, CO ''rn'CO + (Alloxan) = CO ' + CO(CO.OH) 2 (i.) This substance in soln. gives an indigo blue coloured soln. with FeSO4 soln. (ii.) To soln. add KCN soln., HC1, and then make alkaline with NH 4 OH ; a white ppt. of oxalura- NH.CO.CO.NHa . ,. . , , is obtained. URIC ACID GROUP. These all give a characteristic reaction, viz. O'l gram substance is evaporated to dryness carefully with 5 c.c. Cl water ; a yellow residue is obtained, which turns red on gently heating: moisten this with NH 4 OH (2 or 3 drops) ; a reddish-purple or purple colour is obtained. Guanine, C5H 5 N 5 O. (1) To soln. in HC1 add K 2 CrO4 soln. ; an orange- coloured ppt. obtained. (2) To soln. in HC1 add K 4 FeC 6 N 6 soln. ; a brown- coloured ppt. obtained. (3) To soln. in HC1 add saturated soln. of picric acid ; an orange-yellow ppt. obtained. Xanthine, C 5 H 4 N 4 O2 ; insol. in alcohol and ether. (1) To saturated aqueous solution add HgCl2 solution ; a white ppt. (2) To saturated aqueous solution add AgNO 3 solution ; a white ppt. (3) To a mixture of bleaching-powder and NaOH solution in a watch-glass, add a small piece 3<5 of solid ; a dark-green spot, changing to brown and then disappearing, obtained. Uric acid, CsHiN^s. ; insol. in alcohol and ether. (1) Murexide test : evaporate o f i gram with 2 c.c. HNO 3 carefully to dry ness; an orange residue obtained, which is coloured violet-red by NH 4 OH soln.,and violet-blue by KOH soln. (2) Dissolved in Na 2 CO 3 soln. and few drops placed on piece of paper moistened with AgNO 3 soln., produces dark-brown spot. Theobromine, C5H 2 (CH 3 ) 2 N4O 2 ; slightly soluble in hot water, alcohol, and ether, (i) To saturated cold solution add ammoniacal solution of AgNO 3 ; a gelatinous ppt. is formed which dissolves on warming. Caffeine, C 5 H(CH 3 ) 3 N 4 O 2 , slightly soluble in cold water and alcohol, very slightly in ether. (1) Gives murexide test as uric acid. (2) Aqueous solution gives a yellow ppt. with a solution of phosphomolybdic acid. 5. ISOCYANATES. Indicated by powerfu.1 odour. Heated with alkalies become primary amines. CH 3 CNO + H 2 O = CH 3 NH 2 + CO 2 6. ANILIDES. Test A (ii.) (a) will have detected an anilide. It may be further identified by (i.) Determining m.p. (ii.) Preparing a nitroso-derivative (HC1 + NaNO 2 soln.). Nitro-anilides should be specially looked for. p. nitro-acet- anilide gives p : / nitro-phenol when heated with strong KOH solution 37 ;. ESTERS OF NITROUS AND NITRIC ACIDS. A (ii.) (b) will have detected these. Identity by (i.) Determining b.p. of ester, or (ii.) Identifying the alcohol obtained on hydrolysis with alkalies. B. 8. NlTRO-COMPOUNDS. A. Aromatic nitro-compounds. (] All insoluble in water or dilute HC1 or dilute NaOH soln. Di and tri-nitro compounds colour NaOH soln. a deep yellow. (ii.) Mix in test-tube 4 or 5 drops of nitro-compound, i c.c. of water, 2 c.c. cone. HC1, and add slowly about i gram Zn dust ; warm if necessary. Dilute with 5 c.c. of water, and add strong NaOH till ppt. first formed is redissolved ; an amine is produced, which may be separated either by funnel direct or extraction with ether, etc. The amine can be recognized by usual tests. Test specially for aniline by bleaching- powder test ; also given by fatty. (iii.) Dissolve 3 drops of a nitro-compound in 3 c.c. of 50% alcohol. To this soln. add 6 drops of CaCl 2 soln. (i to 10) and a pinch of Zn dust. Heat till solution boils, and after allowing to stand 5 minutes filter. To filtrate add strongly ammoniacal soln. of AgNO 3 ; a deposit of Ag obtained R.NO 2 + 4H = R.NH.OH + H 2 O NOTE. Do not apply this if original body reduces AgNO 3 . Nitroso-, azo-, and azoxy-compounds give this reaction. (iv.) In this reaction the quantities must be taken fairly accurately : Dissolve 3 drops of a nitro-com- pound in 3 c.c. of a mixture of equal parts of 38 aniline, o. toluidine, and p. toluidine. Add 2 c.c. water, 2 c.c. of HC1 (s.g. 1-2) and I gram of Fe filings. Boil almost to dryness in a basin, treat with water, and then pour a little of the dark-coloured solution into a test-tube half full of dilute acetic acid. Magenta or fuchsine colour is produced. B. Fatty nitro-compounds. Agreeable odour, spar- ingly soluble in water, soluble in alkalies. (i.) Dissolve 0*5 c.c. of substance in 5 c.c. strong KOH soln., add 2 c.c. KNO 2 soln., and then carefully add dil. H 2 SO4- (a) Intense red coloration indicates primary nitro-compound. (b) A dark blue coloration indicates second- ary nitro-compound. (c) Tertiary nitro-compounds produce no change. R.CH 2 NO 2 + HONO = R-CfQ + H 2 O (K salt is red) Nitrolic acid. Pseudo-nitrol (blue). (ii.) Reduced as in (2) above, yield amines. (2) Nitro-phenols. (a) Produce very soluble K and Na salts with NaOH and KOH, usually yellow to red in colour and decomposed by HC1. (b) Reduction with Sn and HC1 produce amido-phenols, in which the amido group can be detected in usual manner. 39 (3) Nitro-anilines. (a) Yellow crys. solid. Det. m.p. (b) Reduction with Sn and HC1 produce diamines (see IX. 3 (a) ). (4) Nitro-acids can be reduced by Sn and HC1, etc. 9. HYDRAZONES. (Those of aldehydes and ketones of fatty series mostly yellow oils ; others, yellow or brown crys. solids,) (i.) To 2 grams add 10 c.c. cone. HC1 and digest under reflux till hydrolysis complete ; cool and add NaOH soln. till strongly alkaline ; C6H 5 .NH.NH 2 settles out and maybe separated either by funnel or by extraction with ether, etc., and identified. The aqueous portion con- tains an aldehyde, ketone (if soluble), or glucose, which may be tested for. (ii.) Determine m.p. (This must be done rapidly, as they decompose on slowly heating.) (iii.) Try to prepare an osazone by adding to 0*5 gram of substance a soln. of C 6 H 5 NH.NH 2 in glacial acetic, etc. ; separate the osazone which settles out, and det. m.p. Only those hydrazones containing an OH group in the a position to the hydrazine radical are capable of forming osazones. Some of commonest hydrazones are Pyroracemicphenylhydrazone,CH 3 C(HN 2 .C 6 H 5 )CO 2 H, m.p. 192. Mannose phenylhydrazone, C 6 Hj 2 O 5 N.NH 2 C 6 H 5 , m.p. 195. Benzylidene-phenyl-hydrazone, C 6 H 5 CH : N.NHC 6 H 5 , m.p. 152-5. I* Acetophenone-phenyl-hydrazone, ^|^ 5 >CN.NHC 6 H 5 , m.p. 105. 40 10. OSAZONES. Mostly yellow-coloured solids. Glucosazones, osazones of a-aldehyde alcohols, a-ketone alcohols and a- diketones. (i.) Pechmann's reaction : Digest the substance with alcohol and FeCl 3 , a reddish-brown solution is produced which is soluble in ether, (ii.) Digest 2 grams with cone. HC1 till hydrolysis complete (C6H 5 NH.NH 2 and an osone is pro- duced) ; C 6 H 10 04(N 2 CH. 6 H5)2 + H 2 = CH 2 (OH).(CH.OH) 3 .CO.CHO + 2C 6 H 5 NH.NH 2 make strongly alkaline with NaOH, extract the C 6 H 5 NH.NH 2 liberated, and identify. Remain- ing solution divide into two parts (i) Reduce with Zn dust, and after reduction test for a sugar (carbohydrate) ; and (2) add to soln. of O'l gram of o. CeH 4 (NH 2 ) 2 in alcohol ; a yellow ppt. of a quinoxalin indicates an ortho dicar- bonyl compound (e.g. an osone). (iii.) Mostly all soluble in cold cone. H 2 SO 4 , giving coloured solutions which undergo change on standing. ii. OXIMES. (i.) Digest 2 grams with 10 c.c. cone. HC1 under reflux ; hydrolized to NH 2 QH salt and ketone or aldehyde. (a) Test soln. for aldehyde or ketone. (b) Evaporate to small bulk to expel aldehyde or. ketone, redissolve NH 2 OH.HC1 in water, and add AgNOa, which is reduced to Ag. (ii.) Treat I gram with 5 c.c. dilute acetic acid, 5 c.c. alcohol and piece of Na amalgam ; an amine is 41 produced which can be recognized by usual tests. The amine may, if necessary, be sepa- rated and identified by either determining mol. wt. by PtCl* salt, or its m.p. or b.p. deter- mined. (Hi.) Beckmann's reaction. Dissolve I gram in anhyd- alcohol free ether, and add gradually 1*5 gram PC1 5 ; distil off ether, add water, and crystallize the solid that settles out from alcohol. In this reaction substituted amides are produced, viz. (C 6 H 5 ) 2 C.NOH = C ( ;H 5 NH.CO.C 6 H5. These are decomposed by boiling with alkalies into free amine and the Na salt of the acid, and these can be identified by usual method. 12. AZQ-COMPOUNDS. Digest i gram of substance with 20 c.c. of saturated soln. of SnCl2 in HC1 till compound completely re- duced ; add strong NaOH till Sn(OH) 2 first pptd. is redissolved, when free amines will be liberated, and may be separated and identified, viz. S0 3 H.C 6 H 4 N :N.C 6 H 4 .NH 2 + 4 H = HS0 3 .C 6 H 4 .NH 2 + NH 2 .C 6 H 4 .NH 2 If the azo-dye contains a sulphonic group, one of the products of reduc- tion will always be an amino-sulphonic compound which is soluble in NaOH soln. After separating the free amines, either by steam distillation or ex- traction with ether, these sulphonic derivatives may be pptd. by carefully neutralizing the soln. 13. ALKALOIDS. Easily soluble in dilute acids, repptd. by alkalies (morphine is soluble in excess of NaOH). The fol- lowing reactions indicate an alkaloid : (i.) Heated in dry t.t. give smell of burnt feathers, (ii.) Solution of alkaloids give ppts. with following: 4 2 (a) I in KI dark yellowish-brown ppts. of periodide of alkaloid. (b} Sodium phosphomolybdate soln. yellowish- white ppt. (aniline, quinoline, salts of Ag, Hg, and Pb give ppt). (c) PtCU yellow or yellowish-white ppt. of double Pt salt. (d] BiI 3 in KI yellowish ppts. (e) HgI 2 in KI yellowish-white ppt. (/) Tannic acid white or yellowish-white clotty ppt. (except morphine, which is only ppt. from strong solns. of its acetate). The particular alkaloid must be identified by special tests. The commonest are Cinchona bases. Quinine, C 20 H 21 N 2 O 3 .3H 2 O (thalloquinone reaction best), m.p. 177 (anhyd.). Cinchonine, C 19 H 22 N 2 O, m.p. 250. Opium bases. Morphine, C 17 H 19 NO 3 .H 2 O (FeCl 3 test acetate gives a blood-red). Narcotine, C 22 H 23 NO 7 , m.p. 176. Strychnos bases. Strychnine, C 21 H 22 N 2 O 2 , m.p. 284 (K 2 Cr 2 O 7 test). Brucine, C 23 H2 2 N 2 O 2 , m.p. 178 (HNO 3 test). Solanum bases. Atropine, C 17 H 23 NO 3 , m.p. 150 (HNO 3 test). Cocaine, C 17 H 21 NO 4 , m.p. 98. XII. CARBON, HYDROGEN, AND SULPHUR PRESENT. Mercaptans, Thioethers, and Thiophenes. Each group should be tested for separately. i. MERCAPTANS. Liquids (higher members solids), with disagreeable odour. 43 (i.) Add a few drops of substance to 5 c.c. of an alco- holic solution of HgCl2 ; a white ppt. of a Hg salt is obtained. 2RSH + HgCl 2 = (RS) 2 Hg + 2HC1 (ii.) Using PbA 2 soln. instead of HgCl 2 gives yellow ppt. (iii.) Mix 5 c.c. of alcoholic soln. of substance with 2 c.c. cone. NH 4 OH, and evaporate to dry ness ; colourless needles of a disulphide obtained. 2RSH + O = RS.SR + H 2 (iv.) Add few drops of substance to soln. of I % isatin in H 2 SO 4 ; a green coloration is produced (fatty). (v.) To i c.c. of substance add small pieces of Na ; H is evolved. RSH + Na = RSNa + H (vi.) Digest 2 c.c. with cone. HNO 3 |under reflux ; a sulphonic derivative is obtained, which can be converted into salt and identified. RSH + 30 = R.SO 3 H 2. THIO-ETHERS. Mostly liquids, disagreeable odour. (i.) Mix i c.c. C 2 H 5 I with i c.c. of substance, and warm (if necessary) ; now add moist Ag 2 O and well shake with water, warm, and filter. Test filtrate (a) With litmus alkaline. () With soln. of salt of any heavy metal oxide or hydrate pptd. R 2 S + C 2 H 5 I = R 2 (C 2 H 5 )SI (trialkyl sulphine iodide) R 2 C 2 H r ,SI + AgOH = RaCaHfrSOH + AgT Soluble in H 2 O 44 (ii.) To soln. of substance in alcohol add PbO in NaOH ; ppt. of Pb salt obtained, (iii.) Det. b.p. THIOPHENES. (i.) Dissolve crystal of isatin in 2 c.c. cold cone. H 2 SO 4 , and to this soln. add a few drops of substance ; a deep blue coloration produced. (Indophenin reaction.) Given by all Thiopene compounds. Similar colour produced with furfurane C4H 4 O, pyrrol QH 5 N, carbazol (C 6 H 4 ) 2 NH. (ii.) Nitro- and sulphonic acid derivatives may be easily produced, isolated, and identified by m.p. or b.p. XIII. CARBON/ HYDROGEN, SULPHUR, AND OXYGEN (i) SULPHONIC ACIDS (or their salts) and (2) ALKYL SULPHATES (or their salts). [Aldehyde and Ketone Bisulphites.] (i.) Digest 2 grams of substance with 20 c.c. of 10% soln. of NaOH under reflux. Distil f, and test distillate for alcohol. Residue in flask test for a sulphate. Body can be identified by separat- ing alcohol an'd determining its b.p. = alkyl sulphate. (ii.) Fuse i gram of substance with 2 grams solid KOH in a nickel (or porcelain) crucible to 200 C. Cool, dissolve in water, acidify with HC1, when a phenol will be liberated and may be separated by extraction with ether (or, if insol. in water, filtered off). The phenol can be identified by usual tests = sulphonic acid. To confirm the sulphonic compound (a) Mix i gram of substance with 2 gfams PCIg, and heat on water-bath till action over ; 45 pour into water, when oil settles out, which extract with ether, etc. Det. b.p. = R.SO 2 C1. (b) Mix I gram of oil obtained in (a) with 2 grams (NH 4 ) 2 COa, and heat on water-bath till smell of chloride gone. Treat with water and filter ; residue is a sulphonamide which can be recrystallized from alcohol, and m.p. determined. XIV. CARBON, HYDROGEN, SULPHUR, AND NITROGEN PRESENT. Mustard Oils (Isothiocyanates),Thiocyanates,Thioureas. Test specially for each class, viz. i. MUSTARD OILS. Colourless liquids (some solids) with characteristic odours. (i.) Heat 0*5 c.c. substance with 0*5 gram of yellow HgO ; black ppt. of HgS with evolution of disagreeable odour of an Isocyanate. R.NCS + HgO = R.NCO + HgS (ii.) Warm 0*5 c.c. substance with 0*5 c.c. aniline ; cool and allow to crystallize. A thiourea formed which may be identified by m.p. R.NCS + C 6 H 5 NH 2 = R.HN.CS.NHC 6 H 5 (iii.) Use cone. NH 4 OH instead of aniline. R.NCS + NH 3 = R.HN.CS.NH 2 (iv.) Heat 2 grams of substance with 10 c.c. absolute alcohol under reflux till odour of oil gone ; pour into water and re-crystallize solid that settles out from alcohol. Determine m.p. R.NCS + C 2 H 5 OH = R.HN.CS.OC 2 H 5 (thiourethane) 4 6 (v.) Mix i c.c. with 10 c.c. HC1 and Zn dust ; sub- stance reduced to an amine and CH 2 S (thio- form aldehyde) the latter body has odour of onions. The amine can be separated and identified by usual tests. R.NCS 4- 4H = RNH 2 + CH 2 S (vi.) Heated with cone. HC1 under reflux, CO 2 and SH 2 are evolved, which may be detected. 2. THIO-UREAS. (i.) Heat 2 grams with 10 c.c. cone. HC1 under reflux ; distil f of liquid, and examine as follows :- (a) Distillate contains a mustard oil which may be detected as in XIV. i. (b} Residue contains a guanidine derivative ; heat with strong NaOH under reflux, when an amine and CO 2 produced may be iden- tified. CS(NHR) 2 = R.NCS + R.NH 2 CS(NHR) 2 + R.NH 2 = C.NR.(NHR) 2 + SH 2 C.NR.(NHR) 2 + 2NaOH + H 2 O = 3R.NH 2 + Na 2 CO 3 3. THIOCYANATES. (i.) Mix i c.c. with 5 c.c. HC1 and Zn dust ; reduced to HCN (evolved), mercaptan, and other products. (ii.) Heat with cone. HC1 under reflux, converted into thioether, CO 2 , and NH 3 : all these products can be identified. (iii.) Oxidized when heated with cone. HNO 3 to sul- phonic acids, etc. 47 XV. CARBON, HYDROGEN, SULPHUR, OXYGEN, AND NITRO- GEN OR HALOGEN PRESENT. A. Amino-sulphonic acids (e.g. sulphanilic acid) ; sulphona- mides. B. Chloro-sulphonic acids. Test for each class specially. 1. AMINO-SULPHONIC ACIDS. (i.) Diazotize the compound and couple with either dimethyl aniline or a or ]3 naphthol, azo dyes will be produced, viz. Sulphanilic acid and dimethyl aniline yield methyl orange. Sulphanilic acid and a naphthol yield orange I. and/3 orange II. Metanilic acid and diphenylamine yield metanilic yellow. To diazotize the amino-sulphonic acids, take about o'2 gram of substance in a test-tube, and dissolve it in dilute Na 2 CO 3 soln. ; to this add i c.c. of saturated NaNO 2 soln., well cool, and add dil. HC1 till free HNO 2 is present (KI and starch paper test). To couple with naphthol, dissolve o'l gram naphthol in NaOH soln., and add the soln. so obtained to the diazolized soln., and, if necessary, make alkaline. To couple with dimethyl aniline dissolve o'2 c.c. of it in dil. HC1 till just acid (use fuchsine paper, which is decolorized by free HC1), and add soln. so obtained to the diazotized soln., and make strongly alkaline. 2. SULPHONAMIDES. (i.) Dissolve in alkalies producing salts, e.g. R.SO 2 NHK. (ii.) Alcoholic sols, give a ppt. with AgNO 3 of R.SO 2 NHAg. (Hi.) Treated with C 6 H 5 COCl and NaOH yield acid derivatives, viz. R.SO 2 NH.C 6 H 5 CO. 4 8 (iv.) Fused with NaOH phenols are obtained, NH 3 evolved, etc. Saccharin is the anhydride of o.sulphamin-benzoic acid, viz. CeH^e/yNH. (i.) Heated with HC1 under reflux converts it to o.sulphobenzoic acid and NH 4 C1 ; these can be tested for. (ii.) Fused with solid NaOH at 250 C., cooled, dis- solved in water and acidified with HC1 when salicylic acid separates and may be identified by usual tests. 3. CHLORO-SULPHONIC ACIDS. These may be identified as in XII. (ii.) (). XVI. SPECIAL REACTIONS. 1. The following para derivatives, when oxidized by dil. chromic acid in water or acetic acid, are oxidized to quinone, which can be identified by odour, volatility in steam, and m.p. 116 C. Phenylene-diamine, amidophenol, phenol sulphonic acid, sulphanilic acid, hydroquinone, amido-azo- benzene, diamidodiphenyl, etc. 2. The following yield a naphthoquinone when oxidized as above, m.p. 125 C. (i.) a amido-naphthol, a naphthylamine, nitro a naphthol, (i, 4) diamidonaphthalene , (i, 4) dioxynaphthalene, (i, 4) amido naphthol. (ii.) Naphthalene, CrO 3 in glacial acetic acid. 3. The following yield anthraquinone, m.p. 277. Anthracene and dibromanthracene. Quinone. Yellow crys., pungent odour ; m.p. 116; reduced to p. C 6 H 4 (OH) 2 by SO 2 . 49 Anthraquinone. Heat O'l gram of substance with Zn dust and 5 c.c. NaOH soln. ; a deep blood-red soln. of oxanthrol is produced, o Naphthoquinone. (i.) Heat OT gram with dil. H 2 SO 4 (5 to i) ; gives violet coloration due to a condensation product. (ii.) HeatO'i gram with KOH soln. reddish-brown soln. ; add dil. HC1 a bright red ppt. SOLUBILITY OF ORGANIC SUB- STANCES IN WATER I. C AND H. All insoluble except the lowest members of the aliphatic series. Soluble in C 2 H 5 OH. II. C, H, AND HALOGEN. All insoluble (CHC1 8 , CHI 3 slightly soluble). Readily soluble in C 2 H 5 OH, (C 2 H 5 ) 2 O, CS 2 , and CHC1 3 . III. C, H, AND O. 1. ALCOHOLS. (i.) Aliphatic. (a) Monohydric. Lower members soluble (CsHnOH requires 40 parts of water). (b) Dihydric. More soluble than monohydric. (c) Trihydric. More soluble still ; solubility increases with accumulation of OH groups, (ii.) Aromatic. Less soluble than aliphatic. Solutions produced are neutral. Solubility in ether decreases with accumulation of OH groups. 2. PHENOLS. . (i.) Monohydric. Lower members soluble ; easily soluble in NaOH. Soluble in C 2 H 5 OH and (C 2 H 5 ) 2 O. (ii.) Dihydric. More soluble ; also soluble in Na 2 CO 3 soln. (Hi.) Trihydric. Ditto. Si 3. ALDEHYDES. (i.) Aliphatic. Lower members soluble ; bisulphite deri- vatives slightly soluble ; ammonia derivatives soluble, (ii.) Aromatic. All insoluble. 4. KETONES. (i.) Aliphatic. Acetone miscible with water in all propor- tions ; others mostly insoluble. (ii.) Aromatic. Mostly insoluble. 5. QuiNONES. Insoluble; characteristic odour and volatile in steam. Soluble in CgH^OH and (C 2 H 5 ) 2 O. 6. ETHERS. Less soluble than corresponding alcohols. Solutions neutral. 7. ACIDS. (i.) Aliphatic. Monobasic. (a) Formic, acetic, propionic, butyric mix in all pro- portions. (b) Isobutyric sol. in 3 pts. water. (c) Higher members less and less soluble. Dibasic. Mostly soluble, and solubility increases with accumulation of .COOH groups. Hydroxy. Generally more soluble than corresponding acid. (ii.) Aromatic. Less soluble than aliphatic; easily sol. in ether. All acids are easily soluble in NaOH soln. or Na 2 CO 3 soln. Aromatic oxy acids are easily sol. in CHC1 3 . Most aromatic acids sublime undecomposed. 8. ACID ANHYDRIDES. Combine with water to produce acid, and hence dissolve if corresponding acid is soluble. Combination is slow in the cold, quicker on heating ; higher members require long heating. 52 9. CARBOHYDRATES. Easily soluble in water except starch and cellulose ; solution neutral. (a) Glucoses. Sparingly sol. in abs. C2H 5 OH ; insol. in ether. (b) Saccharoses. Ditto. (V) Polysacchauds. Ditto. 10. GLUCOSIDES. Following are more or less soluble: Salicin, populin, helicin, myronic acid, tannins (certain), arbutin. 11. ESTERS. Insoluble (decomposed on warming and give acid reaction). IV. C, H, AND N. 1. AMINES. A. Monamines. (i.) Aliphatic. Lower members soluble and soln. alkaline ; salts easily soluble. HC1 salts soluble in abs. C2H 5 OH. (ii.) Aromatic. Less soluble than aliphatic. All primary are soluble in acids; secondary and tertiary are not. B. Diamines. Soluble in water, alcohol, and ether ; salts also soluble. 2. CYANIDES. All insoluble (CH 3 CN and C 2 H 5 CN slightly soluble). 3. ISOCYANIDES. All insoluble (easily soluble in alcohol and ether). 4. HYDRAZINES. Sparingly soluble ; salts easily soluble (note C 6 H 5 NHNH 2 ). 5. ALKALOIDS. Insoluble ; easily soluble in acids, hence salts soluble. 53 V. C, H, O, AND HALOGEN. 1. ACID CHLORIDES. Decomposed by water, evolving HC1, and soluble if corresponding acid is soluble. Note aromatic only slowly acted upon. 2. SUBSTITUTED ACIDS. More soluble than corresponding acid. Solution acid. No HC1 evolved. 3. CHLORAL AND CHLORAL HYDRATE. Soluble in water. VI. C, H, O, AND N. 1. AMIDES. Lower members of aliphatic soluble, all others insoluble. 2. AMINO ACIDS. Soluble in water ; solutions neutral ; insoluble as a rule in C2H 5 OH and (C2H 5 ) 2 O. 3. ANILIDES. Sparingly soluble in cold water, more so in hot. 4. NlTRO-COMPOUNDS. (i.) All nitro-hydrocarbons insoluble, (ii.) Nitrophenols, slightly soluble ; salts easily soluble to yellow or red solutions, (iii.) Nitranilines, more or less soluble (some give coloured solns.). (iv.) Nitroacids, sparingly soluble. 5. AZO-COMPOUNDS. (i.) Free azo-compound usually insoluble. (ii.) Salts with acids or alkalies usually soluble (dyes). 6. UREAS. (i.) Urea very soluble, (ii.) Alkyl ureas more or less soluble. 7. UREIDES. (i.) Mostly soluble in water. 54 (ii.) Note following : ^ i i u . M * Oxalyl urea or parabanic acid, CO ^ 1 -A Oxalunc acid, CO -NH.CO.CO 2 H. Malonyl urea or barbituric acid, CO MR CO Mesoxalyl urea or alloxan, (iii.) Uric acid, difficultly soluble, easily soluble in NaOH ; insol. in alcohol and ether. The following bodies are allied to uric acid : Guanine, C 5 H 5 N 5 O, insoluble. Xanthine, C 5 H 4 N 4 O2, soluble in boiling water. Theobromine, C5H 2 (CH 3 ) 2 N 4 O2, difficultly soluble in hot water. Caffeine, C 5 H(CH 3 ) 3 N 4 O 2 , difficultly soluble in cold water. 7. CYANATES, (i.) Alkaline salts soluble. (ii.) Cyanuric acid, sparingly soluble. (iii.) Esters, insoluble. 8. OxiMES. Sparingly soluble in water (acetoxime easily soluble). 9. HYDRAZONES. Very sparingly soluble in water ; mostly colourless compounds ; soluble in alcohol. 10. OSAZONES. Yellow solids ; mostly insol. in water ; difficultly soluble in alcohol. 11. ESTERS OF NITRIC AND NITROUS ACID. Insoluble. 12. ALKALOIDS. Insoluble (almost); easily soluble in acids, hence salts soluble. 55 VII. C, H, AND S. 1. MERCAPTANS. Insoluble in water. Sol. in CaH 5 OH and (C 2 H 5 ) 2 O. K and Na derivatives sol. in water ; all others insoluble. Disagreeable, penetrating odour. 2. THIOETHERS. Insoluble in water. 3. THIOPHENES. Insoluble in water. VIII. C, H, S, AND N. 1. THIOUREAS. (i.) Thiourea easily soluble, (ii.) Substituted more or less soluble. 2. MUSTARD OILS. Insoluble. Characteristic penetrating odour. 3. THIOCYANATES. (i.) Acid and the alkaline salts soluble, (ii.) Esters insoluble. Leek-like odour. IX. C, H, S, AND O. 1. Sulphonic Acids. Soluble ; also their salts. 2. Alkyl Sulphates. Soluble; also their salts. 3. Sulphones. Insoluble. 4. Aldehyde and ketone bisulphites. Very slightly soluble. X. C, H, S, O, AND N. 1. AMINO-SULPHONIC ACIDS. Sparingly soluble (e.g. sul- phanilic acid). 2. SULPHAMIDES. Insoluble (note saccharin very soluble). 3. NITROSULPHONIC ACIDS. Soluble. 56 XI. C, H, S, O, AND Cl. 1. Chlorsulphonic acids. Slightly soluble. 2. Sulphonic Chloranhydrides. Insoluble ; converted into sulphonic acids on boiling. THE END PRINTED BY WILLIAM CLOWES AND SONS, LIMITED, LdNDON AND BECCLES. 21645 W4 UNIVERSITY OF CALIFORNIA LIBRARY