Why are solutions of transition metal ions often coloured

Transition metal ions have, by definition, at least one partly filled d orbital (eg:3d). When in a solution, the positive charge of the transition metal ions can cause the lone elctron pairs of other molecules in the solution (such as water) to be attracted to the transition metal ion, leading to the formation of dative coordinate bond between the metal ion and the ligand - the name used to describe the molecule bonding the metal ion.

The bonding of the ligand molecules to the metal ion causes the energy level of some of the valence d orbitals to be increased, resulting in an energy gap between different valence d orbitals. Electrons in the lower level of d orbitals can absorb visible frequencies of light (which correspond to the energy gap between the orbitals by E=hv) to become excited and move to the higher energy level. This causes the solution to appear the complementary colour to that of the frequency of light absorbed.

Answered by Stuart A. Chemistry tutor

6683 Views

See similar Chemistry A Level tutors

Related Chemistry A Level answers

All answers ▸

The boiling points of ammonia (NH3), fluorine (F2) and bromine (Br2) are -33, -188 and +59 degrees celsius respectively. Explain the differences in these boiling points, including the names of any relevant forces and particles.


How are London forces (Van Der Waals) formed?


Why is a benzene ring so stable (3 marks)?


Predict the effect of an increase in pressure and temperature on the production of ammonia in the reaction: N2(g) + 3H2(g) <-> 2NH3 (g) , where the change in enthalpy is -92.4 kJ


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences