Question

Which of the following ions is formed when an aqueous solution of ammonia is added to the $\left[Cu\right(H_{2}O{)}_6{]}^{2+}$?

• A. $\left[Cu\right(H_{2}O{)}_2(N{H}_3{)}_4{]}^{2+}$
• B. $\left[Cu\right(H_{2}O{)}_3(N{H}_3{)}_3{]}^{2+}$
• C. $\left[Cu\right(H_{2}O{)}_4(N{H}_3{)}_2{]}^{2+}$
• D. $\left[Cu\right(H_{2}O{)}_1(N{H}_3{)}_5{]}^{2+}$

Answer 1

The correct option is A $\left[Cu\right(H_{2}O{)}_2(N{H}_3{)}_4{]}^{2+}$

when an aqueous solution of ammonia is added to the $\left[Cu\right(H_{2}O{)}_6{]}^{2+}$ then deep blue cuproammonium ion is formed.
$\left[Cu\right(H_{2}O{)}_6{]}^{2+}+4N{H}_3\leftrightharpoons \left[Cu\right(H_{2}O{)}_2(N{H}_3{)}_4{]}^{2+}+4H_{2}O$