2 They will not react unless acid is present. Acidified potassium permanganate (H+/KMnO4), and acidified potassium dichromate (H+/K2Cr2O7) are important oxidising agents.They will not react unless acid is present.Purple H+/MnO4- turns colourless when it has reacted.Orange H+/Cr2O72- turns blue/green when it has reacted.
3 Primary alcohol with acidified dichromate; secondary alcohol with acidified permanganate, tertiary alcohol with acidified dichromate.The reactions are very slow unless heated in a water bath.
4 The primary alcohol has turned the dichromate blue/green. The secondary alcohol has decolourised the permanganate.The tertiary alcohol has not reacted with the dichromate.
5 Primary alcohols are oxidised by acidified dichromate or acidified permanganate. They form an aldehyde, and then a carboxylic acid.Secondary alcohols are also oxidised by these oxidising agents. They form ketones.Tertiary alcohols do not react with oxidising agents such as permanganate and dichromate.