The hydroxide-assisted hydrolysis of cyanogen chloride in aqueous solution

The hydrolysis of cyanogen chloride (ClCN) was studied as a function of temperature and pH. Results were used to resolve discrepancies among previously reported kinetic constants. The pH dependence was studied over a range of 9.54–10.93 at a temperature of 21.0°C. The effect of temperature was investigated over the range of 10–30°C at a pH of approximately 10. Changes in the concentrations of ClCN and the reaction products cyanic acid and chloride ion were monitored with time. For the conditions corresponding to these experiments, the hydroxide-assisted hydrolysis pathway predominated. Collision frequency factor and activation energies recommended to represent the hydrolysis of ClCN in aqueous solution are A=2.06×1011 M−1 s−1 and Ea=60,980 J mol−1 for the hydroxide-ion-assisted reaction, and A=9.97×108 s−1 and Ea=87,180 J mol−1 for the water-assisted reaction.