formation of coloured ions

some wavelengths of light are absorbed which excites electrons in d orbitals and the remaining reflected

if a compound appears blue it is absorbing all other parts of the visible spectrum but reflecting blue

d electrons move from a ground state to an excited state when light is absorbed d electrons relax back to ground state by releasing thermal energy

change in E = hv or E = hc / theta Changes in oxidation state, co-ordination number and ligand alter E leading to a change in wavelength absorbed and therefore colour

1) make a series of dilutions of a standard solution of known concentration 2) Find the absorbance using a colorimeter 3) Plot graph of absorbance vs. concentration and add a line of best fit 4) Find absorbance of unknown sample 5) Use the graph to find concentration (read off the line on the graph)

• absorb some wavelengths • excite electrons in d orbitals • remaining wavelengths are reflected

6.63 x 10 to power of -34 Js

3.00 x 10 power of 8 ms^-1

E = h f

E = h x (c/λ)

4.9 x 10 to the power of -7