Which of the following species have a square planar geometry for the central atom?
$(i) XeF_4 \ (ii) SF_4 \ (iii) [NiCl_4]^{2-} \ (iv) [PtCl_4]^{2-}$

The hybridisation of metals involved in the following complexes,$[Mn(CN)_6]^{3-}$ and $[CoF_6]^{3-}$,are respectively:

Which one of the following is an inner orbital complex?

An aqueous solution of metal ion $M1$ reacts separately with reagents $Q$ and $R$ in excess to give tetrahedral and square planar complexes,respectively. An aqueous solution of another metal ion $M2$ always forms tetrahedral complexes with these reagents. Aqueous solution of $M2$ on reaction with reagent $S$ gives a white precipitate which dissolves in excess of $S$. The reactions are summarized in the scheme given below:
$1.$ $M1$,$Q$ and $R$,respectively are :
$(A)$ $Zn^{2+}, KCN$ and $HCl$
$(B)$ $Ni^{2+}, HCl$ and $KCN$
$(C)$ $Cd^{2+}, KCN$ and $HCl$
$(D)$ $Co^{2+}, HCl$ and $KCN$
$2.$ Reagent $S$ is :
$(A)$ $K_4[Fe(CN)_6]$
$(B)$ $Na_2HPO_4$
$(C)$ $K_2CrO_4$
$(D)$ $KOH$
Give the answer for question $1$ and $2$.

Octahedral complexes of copper $(II)$ undergo structural distortion (Jahn-Teller). Which one of the given copper $(II)$ complexes will show the maximum structural distortion?
($en = \text{ethylenediamine}$; $H_2N-CH_2-CH_2-NH_2$)

Which of the following statements is correct regarding the complexes $[CoF_6]^{3-}$ and $[Co(NH_3)_6]^{3+}$?