If a didentate ligand ethane-1, 2-diamine is progressively added in the molar ratio en : Ni :: 1: 1, 2 : 1, 3 : 1 to $$\left[\mathrm{Ni}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+}$$ aq solution, following co-ordination entities are formed.
I. $$\left[\mathrm{Ni}\left(\mathrm{H}_2 \mathrm{O}\right)_4 \mathrm{en}\right]^{2+}(a q)$$ - pale blue
II. $$\left[\mathrm{Ni}\left(\mathrm{H}_2 \mathrm{O}\right)_2(\mathrm{en})_2\right]^{2+}(\mathrm{aq})$$ - blue/purple
III. $$\left[\mathrm{Ni}(\mathrm{en})_3\right]^{2+}(\mathrm{aq})$$ - violet
The wavelength in $$\mathrm{nm}$$ of light absorbed in case of I and III are respectively
Which of the following is an organometallic compound
A better reagent to oxidise primary alcohols into aldehyde is
In the reaction,
$${C_6}{H_5}CN\mathrel{\mathop{\kern0pt\longrightarrow} \limits_{(ii)\,{H_3}{O^ + }}^{(i)\,SnC{l_2} + HCl}} X\mathrel{\mathop{\kern0pt\longrightarrow} \limits_{}^{conc.\,KOH}} Y + Z$$
Formation of $$X, Y$$ and $$Z$$ are known by