Oxidation of alcohols and preparative techniquesEdexcel International A Level Chemistry: Flashcards

What these 13 flashcards ask

What colour change shows alcohol oxidation by acidified dichromate(VI)?
What does a primary alcohol give when distilled as it is oxidised?
What does a primary alcohol give when heated under reflux with excess dichromate(VI)?
What does a secondary alcohol give on oxidation?
What happens to a tertiary alcohol with acidified dichromate(VI)?
Why does a tertiary alcohol not oxidise?
Write the equation for propan-1-ol to propanal using [O].
Why is the aldehyde distilled off as it forms?
What does reflux do?
Which test distinguishes an aldehyde from a ketone?
Which test shows a carboxylic acid?
Why is an anhydrous salt added to an organic liquid?
How is the purity of a distilled liquid checked?

Exam questions on Oxidation of alcohols and preparative techniques

A student warms propan-2-ol with acidified potassium dichromate(VI) solution and notes the colour change. She then repeats the test with 2-methylpropan-2-ol.
State what is seen with 2-methylpropan-2-ol and explain why.2 marks
Propan-1-ol is oxidised using acidified potassium dichromate(VI). In one experiment the product is distilled off as it forms; in a second experiment the mixture is heated under reflux.
Write an equation, using [O] for the oxidising agent, for the oxidation of propanal to propanoic acid, and state the colour change of the oxidising agent.2 marks
In Core Practical 7 a student oxidises propan-1-ol. Boiling temperatures: propan-1-ol 97 °C, propanal 49 °C and propanoic acid 141 °C. The first preparation is designed to give propanal and the second to give propanoic acid.
Explain why propanal can be isolated by distilling it out of the mixture as it forms.3 marks

Written by the Exaim team, led by Shaun Daswani (Head of Upper Secondary, Improve ME Institute; MSc Financial Mathematics, Imperial College London; BSc, UCL) and Jason Daswani (operational lead, Improve ME Institute; LSE).