Solution of ammonia is now seldom made by the druggist, or on the small scale, the large manufacturing chemists supplying it at a very low rate, and of very superior quality. In the shops it is kept of two or three strengths.
The estimation of the strength of ammonia solutions in commerce is known as ammonimetry, and depends upon their specific gravities. The per-centage richness of solutions of ammonia, or of its carbonates, may be most accurately determined, by ALKALIMETRY. For all the ordinary purposes of commerce, and of the laboratory, the strength of pure solutions of ammonia may, however, be inferred, with sufficient correctness, from their density; and to this the term AMMONIOMETRY is usually restricted.
The specific gravity of the sample being found either by the hydrometer[45] or specific gravity bottle, in the usual manner, its per-centage strength may be seen by inspection of the following Table and the Table on p. 127.
[45] An hydrometer specially weighted and graduated for this purpose is called an AMMONIM′ETER, AMMONIOM′ETER, or AMMO′NIA-ME′TER (AMMONIM′ETRUM, AMMONIOM′ETRUM, &c., L.)
Table I.—Showing the per-centage of PURE AMMONIA, and of AMMONIA-WATER of ·9000, in Water of Ammonia, of the given specific gravities, at 60° Fahr. By Dr Ure.
| Sp. Gr. by experiment. | Water of Ammonia of 900, per cent. | Pure Ammonia, per cent. | Water, per cent. |
| ·9000 | 100 | 26·500 | 73·500 |
| ·9045 | 95 | 25·175 | 74·825 |
| ·9090 | 90 | 23·850 | 76·150 |
| ·9133 | 85 | 22·525 | 77·475 |
| ·9177 | 80 | 21·200 | 78·800 |
| ·9227 | 75 | 19·875 | 80·125 |
| ·9275 | 70 | 18·550 | 81·450 |
| ·9320 | 65 | 17·225 | 82·775 |
| ·9363 | 60 | 15·900 | 84·100 |
| ·9410 | 55 | 14·575 | 85·425 |
| ·9455 | 50 | 13·250 | 86·750 |
| ·9510 | 45 | 11·925 | 88·075 |
| ·9564 | 40 | 10·600 | 89·400 |
| ·9614 | 35 | 9·275 | 90·725 |
| ·9662 | 30 | 7·950 | 92·050 |
| ·9716 | 25 | 6·625 | 93·375 |
| ·9768 | 20 | 5·300 | 94·700 |
| ·9828 | 15 | 3·975 | 96·025 |
| ·9887 | 10 | 2·650 | 97·350 |
| ·9945 | 5 | 1·325 | 98·675 |
⁂ Strengths corresponding to sp. gr. which are not in the above Tables may be found by the ‘method of differences’ explained under Alcoholometry.
⁂ The sp. gr. of any sample of liquid ammonia, expressed in three integers, deducted from ·998, and the remainder divided by 4, gives a number which represents the per-centage strength, nearly. (Ure.) This rule may be sometimes conveniently employed for rough calculations, in the absence of Tables.
Ammonia, Carbonates of. (B. P.) Syn. Ammoniæ carbonas. See Ammonium, Sesquicarbonate of.
Table II.—Exhibiting the relations between the SPECIFIC GRAVITY of Solution of Ammonia and the PER-CENTAGE STRENGTH, for every variation of ·00125 sp. gr., from ·87500 to 1·00000, at 62° Fahr. Abridged from the larger Table of Mr J. J. Griffin.