A-level Chemistry/OCR (Salters)/Colour by Design

thumb|right|300px|Realgar is an orange-red mineral used as a pigment in ancient times. Pararealgar is orange-yellow. They have different colours because they have different crystal structures, despite having the same empirical formula, AsS. The crystal structures of realgar and pararealgar contain differently-connected As4S4 molecules − these are shown above, realgar to the left, pararealgar to the right. Colour by Design is the eleventh unit in the Salters Advanced Chemistry course. Chemical Storylines sections CD1 Ways of making colour CD2 The Monastral Blue story CD3 Chrome Yellow CD4 Chemistry in the art gallery CD5 At the start of the rainbow CD6 Chemists design colours CD7 Colour for cotton CD8 High-tech colour CD9 Summary Chemical Ideas sections 6.7 Where does colour come from? (revision) 5.1 Ions in solids and solutions (revision) 6.8 Ultraviolet and visible spectroscopy 13.6 Oils and fats 7.3 Chromatography 6.1 Light and electrons (revision) 12.3 Arenes 12.4 Reactions of arenes 13.10 Azo compounds 6.9 Chemistry of colour Activities CD1 Changing colours chemically CD3 Seeing colours CD4.1 Using reflectance spectra to identify pigments CD4.2 What factors affect the drying potential of an oil? CD4.3 Investigating paint media CD4.4 Identifying a pigment CD4.5 Finding a perfect match CD5 Comparing hydrocarbons CD6 Making azo dyes CD7.1 Dyeing with a direct dye and a reactive dye CD7.2 Different dyes for different fibres CD9 Check your notes on Colour by Design External links CD unit map CD Check Your Notes