If the freezing point of a `0.01` molal aqueous solution of a cobalt (III) chloride-ammonia complex (which behaves as a strong electrolyte) is `-0.0558^(@)C`, the number of chloride (s) in the coordination sphere of the complex if `[K_(f)` of water `=1.86 K kg mol^(-1)]`

Options

A. Four
B. one
C. three
D. Two

Answer

B

Explanation

This can be found by knowing the no. of ions furnished by the complex. For that, we need to know van't Hoff factor, i:
`Delta T_(f) = I K_(f)m`
`0.0558(K) =1(1.86 Kk gmo1^(-1))(0.01 m)`
`I = 3` ltBrgt Thus, th eformula of complex is
`[Co(NH_(3))_(5)C1]C1_(2) rarr [Co(NH_(3))_(5)C1]^(2+) + 2C1^(-)`