Name: Reaction Between Ferrous Ion and Potassium Dichromate
Uploaded: 2019-07-19
Duration: 4 min 21 s
Description: This video explains the excellent oxidising agent, potassium dichromate. One mole of potassium dichromate can oxidise six moles of ferrous sulphate molecules...

Question

Explain why

{TiO}_{2}

is white but

{TiCl}_{3}

is violet.

Accepted Answer

The atomic number of titanium is $22$ . Its electronic configuration is ${TiCl}_{3}$ .

In ${TiCl}_{3}$ , the oxidation state of titanium is $+ 3$ , whereas in ${TiO}_{2}$ , the oxidation state of titanium is $+ 4$ . In case of ${TiCl}_{3}$ there is one electron present in the $3 d$ subshell. Hence, when light falls on this complex, the $t_{2 g}$ electron is excited to $e_{g}$ level. This excitation takes place in the greenish yellow region. The complementary colour which is transmitted is violet. Hence, the colour of titanium (III) chloride is violet. The colour due to this transition is called d-d transition.

In ${TiO}_{2}$ complex, there is no electron in the $3 d$ subshell as the oxidation state of titanium is $+ 4$ , hence, d-d transition is not possible. Therefore, it is white in colour.

Explain why ${TiO}_{2}$ is white but ${TiCl}_{3}$ is violet.

Important Questions on Group 4 - the Titanium Group

Learn and Prepare for any exam you want !

Explain why TiO2 is white but TiCl3 is violet.

Important Questions on Group 4 - the Titanium Group

Learn and Prepare for any exam you want !

Explain why ${TiO}_{2}$ is white but ${TiCl}_{3}$ is violet.