Which of the following will not give a precipitate with $AgNO_3$?

Select the correct $M-C$ bond order.

$PtCl_4 \cdot 6H_2O$ can exist as a hydrated complex. Its $1 \ m$ aqueous solution has a depression in freezing point of $3.72 \ ^\circ C$. Assuming $100\%$ ionization and $K_f \ (H_2O) = 1.86 \ ^\circ C \ kg \ mol^{-1}$,the correct formula for the complex is:

On adding excess of ammonium hydroxide to a copper chloride solution:

The purple color of $KMnO_4$ is due to which of the following?

Give the correct order of electrical conductivity of aqueous solution of the following complexes:
$A$. $[Pt(NH_3)_6]Cl_4$
$B$. $[Cr(NH_3)_6]Cl_3$
$C$. $[Co(NH_3)_4Cl_2]Cl$
$D$. $K_2[PtCl_6]$