Water bleaching properties

Sulphurous acid gas is absorhed by water and hence, in order to examine its properties in that state, it must he collected over moreury. It is colorless and transparent, having a peculiar irritating odor, and cannot be respired. It is neither combustible, nor a supporter of combustion. It possesses bleaching properties, owing to wliich it is used in the arts to whiten straw bonnets, com, silk, sponges, and other substances if a red rose be expesed to the flame of burning sulphur, it becomes completely white. 

Since the fledgling days of industrial chemical practice, the bleaching properties of chlorine have been in demand. Rampant spread of the great killer diseases such as cholera and typhoid was eliminated by the treatment of wastewater and drinking water with small amounts of bleach. Textile manufacturers and the paper industry had established the value of bleach in their operations early on. 

The use of bifunctional cross-linking reagents, such as divinylsulfone, leads to the additional covalent bonding of oxidized starch molecules. This allows a further increase in the water-absorbing properties. Thus, ecologically problematic oxidants such as bleach or NO2 are becoming obsolete [24]. 

Water absorbs about 50 times its volume of this gas, forming liquid sulphurous acid, as it is called, properly an aqueous solution of the acid. This solution has the suffocating smell, peculiar taste, and bleaching properties of the gas. If exposed to the air, it gradually absorbs oxygen, and passes into sulphuric acid. Nitnc acid also converts sulphurous acid into sulphuric acid. 

CAS 8006-40-4 (white) 8012-89-3 (yellow) EINECS/ELINCS 232-383-7 FEMA2126 (wh.) INS901 E901 Synonyms Cera alba White beeswax White wax Yellow beeswax Yellow wax Definition Purified wax from the honeycomb of the bee. Apis mellifera] commonly called white wax when bleached, yellow wax v en not bleached Properties Brown or wh. (bleached) solid with faint odor si. balsamic taste pract. insol. in water si. sol. in cold alcohol sol. in hot alcohol, chloroform, benzene, ether, C, and oils dens. 0.95 m.p. 62-65 C acid no. 17-24 sapon. no. 84 Toxicology Essentially nontoxic mild allergen may cause contact dermatitis, human... 

Chlorine gas turns moist blue litmus paper red and then decolorizes it (Figure 3.34). The bleaching properties of chlorine water are due to the presence of chlorate(i) ions ... 

The presence of chloric(I) acid makes the properties of chlorine water different from those of gaseous chlorine, just as aqueous sulphur dioxide is very different from the gas. Chloric(I) acid is a strong oxidising agent, and in acid solution will even oxidise sulphur to sulphuric acid however, the concentration of free chloric(I) acid in chlorine water is often low and oxidation reactions are not always complete. Nevertheless when chlorine bleaches moist litmus, it is the chloric(I) acid which is formed that produces the bleaching. The reaction of chlorine gas with aqueous bromide or iodide ions which causes displacement of bromine or iodine (see below) may also involve the reaction... 

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