4.4 Aldehydes and Ketones Flashcards
What is observed when Acidified potassium dichromate reacts with an aldehyde?
Orange to green
What is observed when Acidified potassium dichromate reacts with a ketone?
No observation
What is Observed when an aldehyde reacts with Acidified manganate?
Purple to colourless
What is Observed when a Ketone reacts with Acidified manganate?
No observation
Observation when tollens reagent is added to an aldehyde?
Silver precipitate formed
What is Observed when a ketone reacts with tollens reagent?
No observation
What is Tollens reagent?
Silver nitrate dissolved in ammonia
Observation of Fehling’s solution with an aldehyde?
Blue to brick red precipitate
Aldehyde and Fehling’s solution ion changes
Blue Cu2+ —> Brick red precipitate Cu2O
What is observed when Fehling’s solution and a ketone are mixed?
No Observation
Oxidising agents for Aldehydes?
*Fehling’s solution
*Acidified potassium dichromate (6)
*Tollens Reagent
*Acidified manganate (7)
What is 2,4 DNPH?
2,4 dinitrophenylhydrazine
What is observed when 2,4 DNPH reacts with an aldehyde or ketone?
Orange precipitate
What type of reaction occurs with an aldehyde and 2,4 DNPH?
Addition followed by elimination
What general group gives a positive reaction with iodoform?
methyl carbonyl group
CH3CO-R