Question

One mole of the complex with molecular formula $\left[Co\right(N{H}_3{)}_{5}C{l}_3]$ gives two moles of $AgCl$ with excess of $AgN{O}_3$. The complex is

• A. $\left[Co\right(N{H}_3{)}_{4}C{l}_2]Cl$
  
• B. $\left[Co\right(N{H}_3{)}_{3}C{l}_3].2N{H}_3$
• C. $\left[Co\right(N{H}_3{)}_{4}Cl]C{l}_2.N{H}_3$
  
• D. $\left[Co\right(N{H}_3{)}_{5}Cl]C{l}_2$

Answer 1

The correct option is D $\left[Co\right(N{H}_3{)}_{5}Cl]C{l}_2$

Two moles of $AgCl$ with $AgN{O}_3$ means that two ‘Cl’ atoms are ionisable. The third must be within the coordination sphere.
$\left[Co\right(N{H}_3{)}_{5}Cl]C{l}_2\to [Co(N{H}_3{)}_{5}Cl{]}^{2+}+2C{l}^{-}\stackrel{2AgN{O}_3}{\to }2N{O}_3^{-}+2AgCl$