Consider the following complexes:
$(a) K_2PtCl_6$
$(b) PtCl_4 \cdot 2NH_3$
$(c) PtCl_4 \cdot 3NH_3$
$(d) PtCl_4 \cdot 5NH_3$
Their electrical conductances in aqueous solutions are:

The stepwise formation of $[Cu(NH_{3})_{4}]^{2+}$ is given below:
$Cu^{2+} + NH_{3} \rightleftharpoons [Cu(NH_{3})]^{2+} \quad K_{1}$
$[Cu(NH_{3})]^{2+} + NH_{3} \rightleftharpoons [Cu(NH_{3})_{2}]^{2+} \quad K_{2}$
$[Cu(NH_{3})_{2}]^{2+} + NH_{3} \rightleftharpoons [Cu(NH_{3})_{3}]^{2+} \quad K_{3}$
$[Cu(NH_{3})_{3}]^{2+} + NH_{3} \rightleftharpoons [Cu(NH_{3})_{4}]^{2+} \quad K_{4}$
The values of stability constants $K_{1}, K_{2}, K_{3}$ and $K_{4}$ are $10^{4}, 1.58 \times 10^{3}, 5 \times 10^{2}$ and $10^{2}$ respectively. The overall equilibrium constant for dissociation of $[Cu(NH_{3})_{4}]^{2+}$ is $x \times 10^{-12}$. The value of $x$ is ...............
(Rounded off to the nearest integer)

Which of the following exhibits highest molar conductivity?

If $NaOH$ is added to an aqueous solution of zinc ions,a white precipitate appears and on adding excess $NaOH$,the precipitate dissolves. In this solution,zinc exists in the

The stabilization of coordination compounds due to chelation is called the chelate effect. Which of the following is the most stable complex species?

Copper sulphate solution reacts with $KCN$ to give