Question

When $AgN{O}_3$ is added to a solution of $Co(N{H}_3{)}_{5}C{l}_3,$ the precipitate of $AgCl$ shows two ionisable chloride ions.

• A. Two chlorine atoms satisfy primary valency and one secondary valency
• B. One chlorine atom satisfies primary as well as secondary valency
• C. Three chlorione atoms satisfy primary valency
• D. All of the above

Answer 1

The correct option is D All of the above

As per Werner's theory, metals in coordination compounds show two types of valencies/linkages. primary and secondary.
The primary valencies are​ normally ionisable and are​ satisfied by negative ions.​
The secondary valencies are ​non-ionisable. These are satisfied by neutral molecules​ or negative ions. ​A secondary valency is equal to the coordination number and is fixed for a metal.
The ions/groups bound by the secondary linkages to the metal have characteristic spatial arrangements corresponding to different coordination numbers.
$\left[Co\right(N{H}_3{)}_5]C{l}_3+AgN{O}_3(xs)\to 2AgCl\downarrow$