Aldehydes and Ketones Flashcards
How is the solubility of carbonyls decided?
The smaller the molecule the more soluble it is in water as it can form hydrogen bonds with water
What conditions and reagents are needed to oxidise an aldehyde to a carboxylic acid?
acidified potassium dichromate and under reflux
How can you test for an aldehyde and what are the positive observations?
You can test with Tollen’s reagent and the positive result is a silver mirror>
You can use Fehling’s solution and the positive result is a red ppt.
Acidified potassium dichromate turns from orange to green
Can ketones be oxidised?
No
How can you reduce ketones and aldehydes to secondary and primary alcohols respecitively?
Use aqueous NaBH₄
What products are formed from the oxidation of a primary alcohol?
Aldehyde and water
Why is a racemate is formed?
The carbonyl group is planar so the nucleophile can attack from either side of the double formed so both enantiomers are formed evenly.
Why are longer ketones not soluble in water?
The rest of the molecule gets in the way of the hydrogen bonds and breaks them.
What to remember when drawing reflux equations for primary alcohols?
The double oxidising agent 2[O]
Structural formula
Water at the end
What do anti bumping granules do?
They form smaller bubbles and prevent larger bubbles
