Alcohol oxidation

• Oxidation is where a carbon forms a bond with a more electronegative element
• primary alcohols are oxidised to aldehydes
• secondary alcohols are oxidised to ketones
• tertiary alcohols can't be oxidised
• Tertiary alcohols don't have a carbon - hydrogen bond so can't be oxidised
• Aldehydes are oxidised to carboxylic acids
• Ketones cannot be oxidised
• Potassium dichromate is K2Cr2O7
• We can use acidified potassium dichromate to oxidise alcohols
• Typically the acid that acidifies our potassium dichromate is sulfuric acid
• Potassium dichromate needs to be acidified to provide H+ ions
• Chromate ions get reduced
• Potassium dichromate goes from orange to green when it is reduced
• Oxidising agents can be represented by [O]
• Structural formula must be used when writing oxidation equations
• oxidation of alcohols produces water. Oxidation of aldehydes does not
• The reaction mixture is heated to increase the rate of reaction
• Ketones are produced using reflux
• Ketones have a lower boiling point than alcohols, which is why reflux works
• To produce aldehydes, distillation must be used to separate the aldehydes before they oxidise to carboxylic acid
• To produce carboxylic acids, we should heat under reflux to prevent aldehydes leaving
• After oxidisation has finished, we can extract carboxylic acids and ketones via distillation
• We reflux ketones so we don't have to worry about keeping temperatures below that of the boiling point of alcohols. Therefore the temperature can be set high to increase the rate of reaction
• Water enters at the bottom of condensation tubes
• Distillation requires a thermometer, reflux doesn't
• We can't seal anything as that could cause an explosion (including the top of reflux)