Volume 1

A dictionary of chemistry and the allied branches of other sciences / by Henry Watts. Assisted by eminent contributors.

  • Henry Watts
Date:
1868-1871
Catalogue details

Licence: Public Domain Mark

Credit: A dictionary of chemistry and the allied branches of other sciences / by Henry Watts. Assisted by eminent contributors. Source: Wellcome Collection.

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    The acid has a pungent sour taste and odour, blisters the skin, and acts as an acrid poison. It does not redden litmus paper per se, but very strongly when mixed with water. Decompositions. — 1. The vapour of acetic acid is inflammable, and bums with a blue flame, producing water and carbonic acid. When it is passed through a red-hot tube, the greater part remains unaltered, but a portion is decomposed, yielding free carbqp and combustible gases, together with acetone, napthalin, hydrate of phenyl and benzol. (Berthelot, Ann. Ch. Phys. [3] xxxiii. 295.) 2. A mixture of glacial acetic and strong sulphuric acid blackens when heated, giving off carbonic and sulphurous anhydrides. Fuming sulphuric acid mixes with glacial acetic acid without evolution of gas; but the mixture becomes hot, and if it be raised to a higher temperature, carbonic anhydride is given off, mixed with only a small quantity of sulphurous anhydride. Sulphuric anhydride dissolves in acetic acid without evolution of gas, and on heating the mixture, sulphacetic acid is produced. 3. Acetic acid is not sensibly attacked by nitric acid. 4. Periodic add converts it into carbonic or formic acid, with formation of iodic acid and separation of iodine. 5. Chlorine in sunshine converts acetic acid into monochloracetic and trichloracetic acids, the quantity of the one or the other being greater, according as the acetic acid or the chlorine is in excess. See Chlokacetic Acdd. 6. Glacial acetic acid heated with bromine in a sealed tube forms bromacetic and dibromacetic acids. Iodine has no action on acetic acid even in sunshine. 7. With pentachloride of phosphorus, glacial acetic acid forms hydrochloric acid, chloride of acetyl and oxychloride of phosphorus : C2H3O.H.O + PCP.CP = CTPO.C1 + HC1 + PO.C13. 8. With pentasulphide of phosphorus, it forms thiacetic acid and phosphoric anhydride: 5(C2H3O.H.O) + P2S5 = P205 + 5(C2H3O.H.S). The difference between the mode of action of the pentachloride and pentasulphide of phosphorus, the former giving rise to two distinct chlorine-compounds, C2H3O.Cland HC1, whereas the latter forms only one sulphur-eompoiind, is very remarkable, and shows clearly the propriety of regarding chlorine as a monatomic, and sulphur as a diatomic radicle. Aqueous Acetic Acid. — Acetic acid mixes with water in all proportions, impart- ing to it its taste and smell. The density of the aqueous acid varies with its strength in a remarkable manner. When water is gradually added to glacial acetic acid, the density increases till a hydrate is formed containing 79 pts. of crystallised acid to 21 water, and having the composition C2H402. H20. This hydrated acid has a density of 1-073 and boils at 104°. All further additions of water diminish the density of the acid. The following table constructed by Mohr (Ann. Ch. Pharm. xxxi. 277) gives the quantity of crystallisable acetic acid in 100 pts. of the aqueous acid of different densities. Perc. Sp. Gr. Perc. Sp. Gr. Perc. Sp. Gr. Pore. Sp. Gr. Perc. Sp. Gr. 100 1-0635 80 1-0735 60 1-067 40 1-051 20 1-027 99 1-0655 79 1-0735 59 1-066 39 1-050 19 1-026 98 1-0670 78 1-0732 58 1-066 38 1-049 18 1-025 97 1-0680 77 1-0732 57 1-065 37 1-048 17 1-024 96 1-0690 76 1-0730 66 1-064 36 1-047 16 1-023 95 1-0700 75 1-0720 65 1064 35 1-046 15 1-022 94 1 0706 74 1-0720 64 1-063 34 1-045 14 1-020 93 1-0708 73 1-0720 53 1-063 33 1-044 13 1-018 92 1-0716 72 1-0710 62 1-062 32 1-042 12 1-017 91 1-0721 71 1-0710 61 1-061 31 1-041 11 1-016 90 1-0730 70 1-0700 60 1-060 30 1-040 10 1-015 89 1-0730 69 1-0700 49 1-059 29 1-039 9 1-013 88 1-0730 68 1-0700 48 1-058 28 1-038 8 1-012 87 1-0730 67 1 0690 47 1-056 27 1-036 7 1010 86 1-0730 66 1-0690 46 1-055 26 1-035 6 1-008 85 1-0730 65 1-0680 45 1-055 25 1-034 5 1-007 84 1-0730 64 1-0680 44 1-054 24 1-033 4 1-005 83 1-0730 63 1-0680 43 1-053 23 1-032 3 1-004 82 1-0730 62 1-0670 42 1-052 22 1-031 2 1-002 81 1-0732 61 1-0670 41 1-051 21 1-029 1 1001
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