Reactions with Inorganic Species

Chlorine Reactions with Inorganic Species The form ih which chlorine is added to a water affects some of the chemical properties of the water. The addition of chlorine gas to a water will lower Us alkalinity because of the production of the strong acid and HOC by the reaction in Eq. 7-52. However, if chlorine is dosed as a salt of hypochlorous acid  

These considerations are important because they show that the form in which chlorine is added can affect the water chemistry in different ways. The addition of significant amounts of Cl2(g) to a low alkalinity water could depress pH to an unacceptably low value. Bleach addition would not cause such a pH depression. The use of HTH as a disinfectant in swimming pools is not to be recommended because the increase in hardness and alkalinity that accompanies its addition can aggravate scale (CaCOa precipitation) problems. 

If we were to add (or dose) a water with a known amount of one or another of the forms of chlorine, and then after a time interval (contact time) were to analyze the water for chlorine (the chlorine residual), we would find less chlorine present than we added. We say that the water has a chlorine demand, where after a certain contact time, 

The chlorine demand is the result of a variety of reactions in which chlorine is consumed by various constituents of the water and by decomposition. The reactions of chlorine with water constituents can be conveniently grouped into (1) those promoted by sunlight, (2) those with inorganic compounds, (3) those with ammonia, and (4) those with organic compounds. We will consider each of these types of reaction in this section as an illustration of the importance of kinetics and reaction mechanisms of redox reactions. 

Sunlight. Aqueous chlorine solutions are not stable when exposed to sunlight. Radiation in the ultraviolet region provides energy for the reaction of chlorine with water, 

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Much of the CI2O manufactured industrially is used to make hypochlorites, particularly Ca(OCl)2, and it is an effective bleach for wood-pulp and textiles. CI2O is also used to prepare chloroisocyanurates (p. 324) and chlorinated solvents (via mixed chain reactions in which Cl and OCl are the chain-propagating species).Its reactions with inorganic reagents are summarized in the scheme opposite. 

Nitrosyidisulfonic acid, reaction mechanisms, 22 129, 130 Nitrous acid, 33 103 decomposition, rate constants, 22 157 as oxidizing agent, 22 133 reaction mechanisms, 22 143-156 electrophilic nitrosations, 22 144-152 with inorganic species, 22 148, 149 nitrite oxidation by metals, 22 152-154 oxidation by halogens, 22 154, 155 in solution, 22 143, 144 reduction by metals, 22 155, 156 Nitrous oxide reductase, 40 368 Nitroxyl, reaction mechanisms, 22 138 Nitrozation, pentaamminecobalt(III) complexes, 34 181... 

Another group of ozone direct reactions are those with inorganic species such as Fe2+, Mn2 +, NOz, OH, H02 , etc. [44], These could be defined as redox reactions because in the overall process ozone acts as a true... 

In the polluted atmosphere, the principal reactions of HO with inorganic species are its termination reactions with nitrogen oxides to form nitrous and nitric acids ... 

Table 4 Rate constants for the reactions of NO3 radicals with inorganic species.

BH3-OC4H8 (OC4H8 = tetrahydrofuran) is the normal source of BH3 for reaction chemistry hence, the work reported for this species is understandably quite extensive. Some reactions of the species are reported herein those with inorganic species are given first followed by those with organic species. 

This method exemplifies a broad class of processes that proceed via transfer of reacting species between two liquid phases. Such processes may require a catalyst that can combine with species present in one phase and effect their transfer in this form to the second phase where the main reaction occurs. Starks23 has termed such a process phase-transfer catalysis and has demonstrated its utility in reactions involving inorganic anions. For example, he has shown that the rates... 

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