Colour Wheel

For my chemistry notes I needed a colour wheel which can be used to work out the colour of a pigment or dye when the wavelengths at which light is absorbed are known or to work out the wavelengths that are absorbed on when the colour is known.

The opposite colour across the wheel is the complementary colour. A red pigment absorbs green light. A dye that absorbs yellow light appears violet.

I coloured in the diagram linked to below using gimp.

The original diagram

This continues my series of educational resources. Google did not find what I was looking for straight away, hopefully now it will.

Electrophilic substitution reactions of benzene and it derivatives

Following up on my organic reactions post here is a diagram of the Electrophilic substitution reactions of benzene and it derivatives
This diagram includes the reactions that turn benzene into chlorobenzene, bromobenzene, benzenesulphonic acid, cyclohexane, [alk]ylbenzene, phenyl[alk]anone, nitrobenzene -> phenylamine -> benzendiazonium chloride.

Files for download
exported: png, pdf, svg
source: odg (open office draw) , chemtool