Why transition elements form a coloured compounds?
Most of the compounds of transition elements are coloured. This can be explained by $d-d$ transition.
In the presence of combining molecules or anions called ligands, the $d$-orbital loses its degeneracy and splits in two sets of orbitals normally i.e., $\mathrm{e}\left(d x^{2}-y^{2}, d z^{2}\right)$ and $\mathrm{t}_{2 g}(d x y, d y z, d x z)$ depending uponthe geometry of the complex.
These sets of orbitals have different energies after splitting and when an electron from low energy $d$-orbital is excited to higher energy $d$-orbital, the energy of excitation corresponds to the frequency of light absorbed.
The $\mathrm{E}^{\circ}$ value for the $\mathrm{Mn}^{3 *} / \mathrm{Mn}^{2+}$ couple is more positive than that of $\mathrm{Cr}^{3+} / \mathrm{Cr}^{2+}$ or $\mathrm{Fe}^{3+} / \mathrm{Fe}^{2 *}$ due to change of
Which is a stronger reducing agent $Cr ^{2+}$ or $Fe ^{2+}$ and why?
Stainless steel is an alloy of iron with
Generally metal ion and their salts are coloured due to presence of unpaired electrons in metal ions. Which of the following compounds are coloured
Chloro compound of vanadium has only spin magnetic moment of $1.73\,BM$ . This vanadium chloride has the formula :- (at no. of $V = 23$ )