With which of the following will ammonia $NOT$ form a complex compound?

$CuSO_4$ solution reacts with excess $KCN$ to give

In the isoelectronic series of metal carbonyls,the $CO$ bond strength is expected to increase in the order:

Identify the highest field strength ligand from the following.

$CrCl_3 \cdot xNH_3$ can exist as a complex. $A$ $0.1 \ m$ aqueous solution of this complex shows a depression in freezing point of $0.558^{\circ} C$. Assuming $100 \%$ ionisation of this complex and that the coordination number of $Cr$ is $6$,the complex will be: (Given $K_f = 1.86 \ K \ kg \ mol^{-1}$)

$A$ complex containing $K^{+}$,$Pt(IV)$ and $Cl^{-}$ is $100\%$ ionised giving $i = 3$. Thus,the possible complex is