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

The $\pi-$acid ligand which uses its $d-$orbital during synergic bonding in its complex compound is:

The stability constants for complexes formed by a metal ion $(M^{2+})$ with ligands $NH_3$,$CN^-$,$H_2O$,and $en$ are $10^{11}$,$10^{27}$,$10^{15}$,and $10^8$ respectively. Based on these values,which of the following is correct?

Which of the following complexes is the strongest reducing agent?

Aqueous ammonia readily dissolves $AgCl$ because

Compound $PdCl_4 \cdot 6H_2O$ is a hydrated complex; $1 \ m$ aqueous solution of it has a freezing point of $269.28 \ K$. Assuming $100\%$ ionization of the complex,calculate the molecular formula of the complex ($K_f$ for water $= 1.86 \ K \ kg \ mol^{-1}$,freezing point of pure water $= 273 \ K$).