Question

A compound has the empirical formula $CoC{l}_3.5N{H}_3$. When an aqueous solution of this compound is mixed with excess of silver nitrate, 2 moles of $AgCl$ precipitate out per mole of compound. On reaction with excess of HCl, no $N{H}_4^{+}$ is detected. Hence, the compound is :

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

Answer 1

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

When an aqueous solution of the compound is mixed with an excess of silver nitrate, 2 moles of AgCl precipitate out per mole of compound. It depicts that, 2 atoms of Cl is present outside the coordination sphere. On reaction with excess HCl, no $N{H}_4^{+}$ is detected, it depicts that, there is $N{H}_3$ molecule out of the coordination sphere. Hence, the compound should be $\left[Co\right(N{H}_3{)}_{5}Cl]C{l}_2$.