isomerism and carbonyl compounds Flashcards
what is a chiral carbon atom
a carbon atom with four different groups attached to it
what are enantiomers if they can be super iomposed on each other
achiral and there is no optical isomerism
what is an eantiomer
molecule has same structural formula as another
but with four groups arranged around a chiral carbon atom so that is is a non-superimposable mirror image of the other molecule
what is an optically active molecule
one that rotates plane polarised light
what is a racemate
a mixture that contains equal quantities of each eantiomer of an optically active compound
what enantiomers do to plane polarised light
the molecules interact with the light and rotate the place of the vibration of the light
one enantiomer will rotate the light clockwise
the other enantiomer will rotate the light counter clockwise
when can the aldehyde group only occur on a chain
an aldehyde group can only occur at the end of a chain
what is the shortest ketone and why
the shortest ketone is 3 carbons long as the carbonyl group must be connected to 2 aryl or alkyl R-groups
what is aryl
aryl-based on an aromatic system
what is alkyl
based on a satuarted hydrocarbon group
what is the strongest type of intermolcular force in carbonyl compounds and why?
permenant dipole-dipole forces
as the carbonyl group is strongly polar
what is the boiling point of carbonyl compounds compared with other organic compounds
it is higher than alkanes and alkenes as they contain van der waals forces which are weaker than dipole-dipole forces
it is lower than carboxylic acids and alcohols however as they contain hydrogen bonds which are stronger
what is the solubility of carbonyl compounds in water like
shorter chain ketones and aldehydes mix perfectly with water and form hydrogen bonds
longer chain ketones and aldehydes do not mix well as the carbonyl compounds are less soluble in water
what are the conditions for esterficartion
heat under reflux
with concentrated sulfuric acid
what are the conditions for base hydrolysis
heat under reflux
with dilute alkaline
what are the conditions for acid hydrolysis
heat under reflux
dilute sulfuric acid catalyst
what are the two key differences between acid and base hydrolysis
acid hydrolysis is reversible
base hydrolysis is not
base hydrolysis gives a carboxylate salt
acid hydrolysis gives a carboxylic acid
what is acylation
the process by which an acyl group is introduced to another molecule
what is saponification
making soap
what are the conditions for making biodiseal
triglyceride ester is reacted with methanol
with a strong alkali as a catalyst
what are the three factors that can vary the rate at how readily acylation occurs
magnitude of charge on the carbonyl carbon
how easily the leaving group is lost
how good the nucleophile is
name three uses of esters
solvents
plasticisers
perfumes
what is biodeseal
a mixture of methyl esters of fatty acids which can be used as a carbon neutral fuel
what does the reaction of an acyl anhydride with a nucleophile always give
a carboxylic acid
