Aldehydes and Ketones ( A-level ) Flashcards
what is a carbonyl group?
C=O
what is the functional group and general formula for and aldehyde?
RCHO( C double bonded to O, single bond to H and R )
what is the functional group for a ketone?
RCOR’ ( C double bonded to O )
how do you name aldehydes?
-al suffix
how do you name ketones?
-one suffix
what kind of intermolecular forces do molecules with the carbonyl group have? why?
Permanent dipole-dipole due to the polar C=O bond
are they soluble are they in water? what influences solubility?
Yes- because they can form hydrogen bonds between water molecules and oxygen of C=O. as the carbon chain length increases the solubility decreases.
what bond in carbonyl compounds is usually involved in reactions? why?
C=O due to the polarity of the bond ( large difference in electronegativity between carbon and oxygen )
why is the addition of HCN important?
increases the length of the carbon chain by one carbon atom- very useful
will the product of HCN added to a carbonyl compound have optical isomers? why?
yes they will. in the aldehyde/ketone, the carbonyl group is planar, so the :CN- can attack from either above or below, forming two enantiomers
what is the name of the product when HCN is added to a carbonyl compound?
Hydroxynitriles
what is Fehlings solution? what colour is it?
Copper complex ions, blue
what happens when an aldehyde is added to Fehlings solution?
reduced to C+ ions –> colour change to brick red ppt
what happens when a ketone is added to Fehlings solution?
no visible change –.> stays blue
what is tollens reagent?
silver complex ions, colourless solution
