Question

Among the following, which species represents a pseudohalide?

• A. $C{N}^{-}$
• B. CaO
• C. $I_2$
• D. $K_{2}Kh{I}_4$
• E. BiOCl

Answer 1

Answer: (A)

Pseudohalides are 'fake halides'. Their chemistry involves resemblence with true halides $\left(F^{-},C{l}^{-},B{r}^{-},I^{-}\right)\cdot C{N}^{\ominus }$ is a pseudohalide. It has similar properties to those of halogens. Pseudohalide is any uni-negative species composed of two or more atoms, which in the free state shows certain characteristics of the halogens, e.g. these combine with hydrogen to form an acid and with silver to form a salt insoluble in water.