17.2.2 - Redox reactions of carbonyl compounds Flashcards
What is the compound that reduces aldehydes and ketones back to alcohols?
Lithium tetrahydridoaluminate
What are the names of 4 reagents that oxidise aldehydes to carboxylic acids?
Acidified potassium dichromate
Fehlings solution
Benedict’s solution
Tollens’ reagent
What is the colour change when an aldehyde reacts with acidified potassium dichromate?
Orange to green
What is the colour change when an aldehyde reacts with Fehlings solution?
Blue to red precipitate
What is the colour change when an aldehyde reacts with Benedict’s solution?
Blue to red precipitate
What is the colour change when an aldehyde reacts with Tollens’ reagent?
Colourless to silver mirror
What is formed when a carbonyl compound with a CH3CO group is added to an alkaline solution of iodine, warmed and then cooled?
A pale yellow precipitate
What compounds are primary and secondary alcohols oxidised to?
Primary = aldehydes and the further to carboxylic acids
Secondary = ketones
What does the reaction between a carbonyl compound and alkaline iodine solution test for?
A CH3CO group
Only found in ethanal
Found in all methyl ketones with a carbonyl group on carbon 2
What carbonyl compound will give a positive test when reacting with iodine?
Propanone
Butanone
Pentan-2-one
Give an example of a carbonyl compound that will give a negative result when reacted with iodine.
Pentan-3-one
