CHAPTER II
MODUS OPERANDI
Before considering the “modus operandi” of chlorine and hypochlorites, it will be advisable to take up the composition of the latter substances and particularly that of “bleach.” Bleach is manufactured by passing chlorine gas over slaked lime and the ensuing reactions are often represented by the equation Ca(OH)2 + Cl2 = CaOCl2 + H2O. This represents the substance formed as a pure oxychloride of calcium which contains approximately 50 per cent of chlorine, but the article commercially produced never contains this amount of chlorine, the usual percentage being from 35-37. The general composition of commercial bleach is fairly uniform. This is shown in the following analyses of which two are of German bleach examined by Lunge and one of Canadian manufacture analysed by the author.
| Lunge. | Race. | ||
| % | % | % | |
| Available chlorine | 37.00 | 38.30 | 37.50 |
| Chlorine as chlorides | 0.35 | 0.59 | 0.52 |
| Chlorine as chlorates | 0.25 | 0.08 | 0.18 |
| Lime | 44.49 | 43.34 | 44.12 |
| Magnesia | 0.40 | 0.31 | 1.28 |
| Iron oxide | 0.05 | 0.04 | 0.11 |
| Alumina | 0.43 | 0.41 | 0.46 |
| Carbon dioxide | 0.18 | 0.31 | 0.22 |
| Silica | 0.40 | 0.30 | 0.52 |
| Water and undetermined | 16.45 | 16.32 | 15.09 |
From these analyses the constitutional of commercial bleach might be represented by the formula
4CaOCl2·2Ca(OH)2·5H2O
which assumes it to contain: