3.8 Aldehydes and Ketones Flashcards
What is meant by a carbonyl compound?
The functional group revolves around C=O
What is the functional group of an Aldehyde?
What is the functional group of a Ketone?
What happens when K2Cr2O7 is added to an Aldehyde?
The Aldehyde would be Oxidised, turning from an Orange colour to Green
What happens when K2Cr2O7 is added to an Ketone?
Nothing because the Ketone cannot Oxidise further.
Why can you not oxidise a Ketone further?
It would require breaking a C-C bond rather than a C-H bond which requires high amount of energy only able to do in combustion
How does Tollens Reagent form a Silver Mirror?
How is Tollens Reagent reduced?
Ag (NH3)2+ (aq) + e- -> Ag (s) +2NH3
How does Tollens Reagent react with Aldehydes and Ketones?
Aldehydes form a silver mirror as they can be further oxidised
Ketones dont cause any change as they have no further oxidation
How is Fehling’s solution reduced?
How does Fehlings Solution react?
Cu2+ (aq) + e- -> Cu+
The Cu+ ions give the colour
How do Aldehydes and Ketones react with Fehlings Solution?
Aldehydes turn from Blue solution to Red due to the free floating Cu ions.
Ketones remain a Blue solution as they cannot further oxidise
What is NaBH4?
Sodium Hydro Tetra Borate
A source of Hydride H- ions
The ions act as Nucleophiles- a lone pair donator
What is a Racemic Mixture?
What is a Racemate?
A mixture of left and right handed enantiomers of a chiral molecule
What is an enantiomer?
Stereoisomers that are non-super imposable mirror images.
For example, molecules with 1 Chiral Carbon
