Effect of temperature and presence of hypochlorite on the rate of hydrolysis of cyanogen chloride in alkaline solution

✍ Scribed by Eden, G. E. ;Wheatland, A. B.

• Publisher: Wiley (John Wiley & Sons)
• Year: 1950
• Weight: 416 KB
• Volume: 69
• Category: Article
• ISSN: 0368-4075
• DOI: 10.1002/jctb.5000690602

✦ Synopsis

Abstract

During an investigation on the destruction of cyanide in waste waters by chlorination it was observed that, even in strongly alkaline solution, the first product of the reaction of a cyanide with a hypo‐chlorite is cyanogen chloride; this then undergoes hydrolysis, possibly with formation of a cyanate. The rate of formation of cyanogen chloride is extremely rapid, but hydrolysis, as has been shown by Price et al.,^1^ proceeds at a measurable rate, given by the equation: magnified image

The value of k~1~ was estimated by Price to be 600 l./mol. min. at 25°c.

In treatment of waste waters containing cyanide the object is to convert the cyanide to relatively non‐toxic substances; cyanogen chloride, which is toxic, is therefore an undesirable intermediate product and it is important to know how quickly it will disappear from solutions undergoing treatment. The rates of hydrolysis of cyanogen chloride at temperatures ranging from 0° to 30° c. were therefore determined in solutions buffered at the p~H~ value of 11, which has been found most suitable for chlorination of waste waters containing cyanide; the effect of the presence of small concentrations of hypochlorite was also investigated, since it had been noted in preliminary experiments that a slight excess of chlorinating agent appeared to accelerate hydrolysis.