Question

One mole of a complex compound $Co(N{H}_3{)}_{5}C{l}_3$ gives three moles of ions on dissolution in water. One mole of the same complex reacts with two moles of $AgN{O}_3$ and yields two moles of $AgCl\left(s\right)$. The complex is:

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

Answer 1

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

It is given that one mole of a complex compound $Co(N{H}_3{)}_{5}C{l}_3$ gives three moles of ions on dissolution in water. One mole of the same complex reacts with two moles of $AgN{O}_3$ and yields two moles of $AgCl\left(s\right)$.

The complex ion is $\left[Co\right(N{H}_3{)}_{5}Cl]$ $C{l}_2$ as two $Cl$ ions are out of the coordination complex.

Therefore, on dissolution in water, three ions are produced and they are $2C{l}^{-}$ and $\left[Co\right(N{H}_3{)}_{5}Cl{]}^{2+}$ ions.

The two $C{l}^{-}$ ions which are free react with $2$ moles of $AgN{O}_3$ to give $2$ moles of $AgCl$.