Consider the following complex ions

$$\begin{aligned} & \mathrm{P}=\left[\mathrm{FeF}_6\right]^{3-} \\ & \mathrm{Q}=\left[\mathrm{V}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+} \\ & \mathrm{R}=\left[\mathrm{Fe}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+} \end{aligned}$$

The correct order of the complex ions, according to their spin only magnetic moment values (in B.M.) is :

Yellow compound of lead chromate gets dissolved on treatment with hot $$\mathrm{NaOH}$$ solution. The product of lead formed is a :

The total number of stereoisomers for the complex $$\left[\mathrm{Cr}(o x)_{2} \mathrm{ClBr}\right]^{3-}$$ (where $$o x=$$ oxalate) is :