someone says that the temperature affects the colour of all coloured solutions?

Question

do you agree with his/her view?
If not, how could you prove that the temperature only changes the colour of a solution when it changes the concentration of one or more of the coloured species in the solution? Suggest an experimetal set-up.

Answer 1

Yes. All colour arises due to electronic transitions. These can be due to the conjugation of bonds, charge transfer complexes or oxdn. states.

If the temperature is suitable, these states and hence the colour can change.