Question

\[{{\left[ Ti{{\left( {{H}_{2}}O \right)}_{6}} \right]}^{+3}}\]is paramagnetic in nature due to
A One unpaired electron
B Two unpaired electrons
C Three unpaired electrons
D No unpaired electron

Answer 1

Hint: The given compound is a complex compound (central metal surrounded by ligand). In the given complex compound, the central metal is titanium (Ti) which is surrounded by 6 water molecules (ligands). This complex is paramagnetic in nature, which means in the compound outermost shell contains the unpaired number of electrons or an electron whereas diamagnetic means that there is no unpaired electron but only paired one.

Complete answer:The central metal in the complex is titanium whose atomic number is 22 so its electronic configuration is given as

\[1{{s}^{2}}\], \[2{{s}^{2}}\], \[2{{p}^{6}}\], \[3{{s}^{2}}\], \[3{{p}^{6}}\], \[3{{d}^{2}}\], \[4{{s}^{2}}\]
As in the outmost shell total number of four electrons are present.

As per the question the whole compound oxidation state is +3 due to which we need to find the oxidation state of the central metal, titanium. As water ligands are neutral so they carry no charge so the whole charge (oxidation state) on the complex is the oxidation state of central metal (ignoring water ligands). So, the oxidation state of titanium is +3 (sign + indicates the loss of electron) so titanium loss three electrons from its outermost shell such as
\[T{{i}^{3+}}\]electronic configuration is \[3{{d}^{1}}\]
As there is one unpaired electron left in the outermost shell thus we can say that the complex is paramagnetic and this is due to one unpaired electron in the outermost electron.
Thus, the correct option is A

Note: The +3 oxidation state is because of the presence of 3 anions which bonded with the central metal through chemical bonding whereas ligands bonded with the central metal through coordinate bonds. Also out of four electrons from the outermost electron, two electrons are filled first in the 4s orbital and then the other two in the 3d orbital but electrons always release or are removed firstly from the 4s orbital and then from 3d due to which titanium in an oxidation state +3 left with one electron in 3d orbital.