When an aqueous solution of copper $(II)$ sulphate is saturated with ammonia,the blue compound crystallises on evaporation. The formula of this blue compound is

Considering that $\Delta_{0} > P$,the magnetic moment (in $BM$) of $[Ru(H_{2}O)_{6}]^{2+}$ would be

Geometrical shapes of the complexes formed by the reaction of $Ni^{2+}$ with $Cl^{-}$,$CN^{-}$,and $H_2O$,respectively,are

The magnetic moment of $[MnCl_{4}]^{2-}$ is $5.92 \ BM$. Explain the reason for this value.

Addition of excess aqueous ammonia to a pink coloured aqueous solution of $MCl_2 \cdot 6H_2O (X)$ and $NH_4Cl$ gives an octahedral complex $Y$ in the presence of air. In aqueous solution,complex $Y$ behaves as a $1:3$ electrolyte. The reaction of $X$ with excess $HCl$ at room temperature results in the formation of a blue coloured complex $Z$. The calculated spin-only magnetic moment of $X$ and $Z$ is $3.87 \ B.M.$,whereas it is zero for complex $Y$.
Among the following options,which statement$(s)$ is(are) correct?
$[A]$ The hybridization of the central metal ion in $Y$ is $d^2sp^3$
$[B]$ $Z$ is a tetrahedral complex
$[C]$ Addition of silver nitrate to $Y$ gives only two equivalents of silver chloride
$[D]$ When $X$ and $Z$ are in equilibrium at $0^{\circ}C$,the colour of the solution is pink

The geometry of $[Pt(NH_3)_4]Cl_2$ is: