C102 CHLORINE DIOXIDE

C102 CHLORINE DIOXIDE 121.9791 -5.2893E+03 -4.1838E+01 -2.0950E-08 2.6848E... 

C102 CHLORINE DIOXIDE 30.482 3.9797E-02 4.5262E-06 -3.2447E-08 1.3089E-11 50 1500 gas... 

The vapor pressure of chlorine dioxide, Cl02, is 155 Torr at —22.75°C and 485 Torr at ().()0°C. Calculate (a) the standard enthalpy of vaporization (b) the standard entropy of vaporization (c) the standard Gibbs free energy of vaporization (d) the normal boiling point of C102. 

The principal use of sodium chlorate is as a source of chlorine dioxide, C102. The chlorine in C102 has oxidation number +4, and so the chlorate must be reduced to form it. Sulfur dioxide is a convenient reducing agent for this reaction ... 

Chlorine Monoxide, Dimethyl Ether, Chlorine Dioxide and Sulfur Dioxide.—The radial distribution curves for C120, (CH3)20, C102 and S02 (Fig. 8) show two peaks, the positions of the... 

Other gas treatments may include chlorine dioxide (C102) both as a gas and in an aqueous solution. The potential for use of this gas in disinfection of fruits and vegetables is mainly due to the fact that it is not affected by pH and organic matter contents to the same degree as chlorine (Betts and Everis, 2005 Busta et al., 2001). However, C102 must be generated on-site and it may be explosive when concentrated. There are only a few reports on the... 

Chlorine dioxide (C102) is a powerful oxidizing agent. It has a selective reactivity that makes it useful in many applications such as water treatment, disinfec-... 

The Olin Corporation has developed an electrochemical chlorine dioxide generator technology that safely and conveniently produces aqueous chlorine free solutions of chlorine dioxide at chlorite molar conversion efficiencies of 95% or better [221-224]. The chlorine dioxide is produced by direct oxidation of sodium chlorite, Fig. 21. The electrochemical C102 generator system is shown in Fig. 22. 

The electrochemical generator is designed for both small (0.136-4.5 kg C102/day) and larger scale (0.5-27 kg/h range and more) chlorine dioxide production rates. The chlorine dioxide solution from this system is suitable for sanitizing and disinfection applications as well as waste water treatment. 

The total quantities of chlorine dioxide formed are quite low and are in the order of 0.5-3 g for the peak-load experiments. Because this is a relatively low range of values, it is not easy to discover any correlations with other species involved in the reactions as the concentration may hardly change. This could also be one of the reasons that there is no relationship found between chlorate and the C102 emission values. 

Yin, G. Ni, Y., (1998) Quantitative description of the chloride effect on chlorine dioxide generation from the C102-H0C1 reaction. Canadian Journal of Chemical Engineering, 76, 921-926. 

Chlorine dioxide is a very reactive compound and may exist in the environment for only short periods of time (see Section 6.3.2). Chlorine dioxide is readily soluble as a dissolved gas. However, chlorine dioxide can be easily driven out of aqueous solutions with a strong stream of air. The partition coefficient between water and C102(g) is about 21.5 at 35 °C and 70.0 at 0 °C (Aieta and Berg 1986 Kaczur and Cawlfield 1993 Stevens 1982). Transport and partition of chlorine dioxide in soils and sediments will not be significant. Chlorine dioxide is expected to be reduced to chlorite ions in aqueous systems (see Section 6.3.2.2). 

Chlorine dioxide gas is unstable and can rapidly decompose at high concentrations. It also decomposes rapidly to chlorine and oxygen with exposure to mild heat. Chlorine dioxide will decompose upon exposure to sunlight (Vogt et al. 1986). The gas-phase absorption spectrum for chlorine dioxide is the same as in aqueous solution (Kaczur and Cawfield 1993). The primary photochemical reaction of CIO2 in the gas phase corresponds to homolytic scission of one of the chlorine-oxygen bonds (i.e., C102 CIO +... 

Chlorine dioxide does not hydrolyze to any appreciable extent between pH 2 and 10 but remains in solution. Dilute neutral or acidic aqueous solutions are stable if kept cool, well sealed, and protected from sunlight. In the absence of oxidizable substances and in the presence of hydroxide ions, chlorine dioxide will dissolve in water and then decompose with the slow formation of chlorite and chlorate ions (e g., 2CIO2 + 20H" C102 + CIOs + H2O). At chlorine dioxide concentrations in the 5-10 mg/L range at pH 12, the decomposition half-life of chlorine dioxide in solution ranges from 20 to 180 minutes (Aieta and Berg 1986 Stevens 1982 WHO 2000). 

Chlorine dioxide has a positive chlorine oxidation state of four (+4), which is intermediate between chlorite (+3) and chlorate (+5) ions. Oxidation of chlorine dioxide usually results in the formation of chlorite ions (e.g., CIO2 + e C102 =0.95 volts). Chlorite ions (CIO2 ) are also effective oxidizing... 

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