Question

A sufficient amount of $AgN{O}_3$ solution was added to a solution containing $23.35g$ of the complex salt $CoC{l}_3\cdot 4N{H}_3$.

The mass of the precipitated $AgCl$ was $14.35g$. Determine the no. of Chlorine atoms outside the coordination sphere of the complex $(Co=59g$ $mo{l}^{-1})$:

• A. 0
• B. 1
• C. 2
• D. 3

Answer 1

Answer: (B)

1

Moles of the complex$=\frac{23.25}{233.5}=0.1$
Moles of $AgCl$ ppt$=\frac{14.35}{143.5}=0.1$
Thus, $1$ mole of the complex gives $1$ mole of $AgCl$ indicating only one chlorine is outside coordination sphere. Thus, complex is $\left[Co\right(N{H}_3{)}_{4}C{l}_2]Cl$.