(A) Answer the following: (a) Low spin tetrahedral complexes are not known. (b) Co^2+ is easily oxidised to Co^3+ in the presence of a strong ligand…

Answer the following :

Low spin tetrahedral complexes are not known.

$\displaystyle \mathrm{Co}^{2+}$ is easily oxidised to $\displaystyle \mathrm{Co}^{3+}$ in the presence of a strong ligand [At. No. of Co = $\displaystyle 27$]

What type of isomerism is shown by the complex $\displaystyle \left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{6}\right]$ $\displaystyle \left[\mathrm{Cr}(\mathrm{CN})_{6}\right]$ ?

Why a solution of $\displaystyle \left[\mathrm{Ni}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{2+}$ is green while a solution of $\displaystyle \left[\mathrm{Ni}(\mathrm{CN})_{4}\right]^{2-}$ is colourless. (At. No. of $\displaystyle \mathrm{Ni}=28$ )

Write the IUPAC name of the following complex : $\displaystyle \left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{5}\left(\mathrm{CO}_{3}\right)\right] \mathrm{C} l$ 32. (B) (a) What is meant by 'Chelate effect' ? Give an example. ( $\displaystyle \mathbf{2} \boldsymbol{+} \mathbf{2} \boldsymbol{+} \mathbf{1} \boldsymbol{=} \mathbf{5}$ )

Write the hybridization and magnetic behaviour of $\displaystyle \left[\mathrm{Fe}(\mathrm{CN})_{6}\right]^{4-}$. (Atomic number : $\displaystyle \mathrm{Fe}=26$ )

If $\displaystyle \mathrm{PtCl}_{2} \cdot 2 \mathrm{NH}_{3}$ does not react with $\displaystyle \mathrm{AgNO}_{3}$, what will be its formula ?