6.2.1-6.2.2 Amines, Amino acids, amides, chirality

Are amines known as alkalis or bases?

• bases

Why are amines bases?

• there is a lone pair of electrons on the nitrogen atom of an amine that is able to accept protons/H+ ions

What can amines be neutralised with acids to form?

• ammonium salts

How can aliphatic amines be made?

• through heating a haloalkane with excess ammonia dissolved in ethanol

state an example of a nitro compound?

• nitrobenzene

how can aromatic amines be made

• by reducing a nitro compound

state the 2 steps in which nitro compounds can be reduced?

• heat a mixture of a nitro compound, tin metal and conc HCl under reflux

• add NaOH to make the salt

what are amides?

• derivatives of carboxylic acids

state the functional group which amides contain?

• -CONH₂

why do amides behave differently to amines?

• because the carbonyl group pulls electrons away from the rest of the -CONH₂ group

what groups does an amino acid have?

• NH₂(basic amino group)

• COOH(acidic carboxyl group)

how are groups attached in an alpha amino acid?

• both groups are attached to the same carbon

state and draw the the general formula and structure of an amino acid?

• RCH(NH₂)COOH

what can the carboxyl group of an amino acid react with an alkali to form?

• to form a salt

what can the amino group in an amino acid react with an acid to form?

• to form a salt

what do amino acids react with alcohols to form?

• ester and water

What is a chiral carbon atom?

• a carbon which has 4 different groups attached to it

define optical isomerism?

• stereoisomers that are non-superimposable mirror images of each other

Define enantiomers?

• mirror images which cannot be superimposed

define stereoisomers?

• have the same structural formula but different arrangement in space

define polymers?

• long chain molecules formed when lots of monomers join together

state the 2 ways which polymers can be made?

• addition polymerisation

• condensation polymerisation

in condensation polymerisation what is lost each time a link is formed?

• a small molecule is lost- usually water

what do condensation polymers include?

• polyesters

• polyamides

in polyesters what link forms between the monomers?

• an ester link -COO-

in polyamides what link forms between the monomers?

• an amide link -CONH-

By what process can condensation polymerisaton be reversed by?

• hydrolysis

do polyamides hydrolyse easir with an acid or a base?

• with an acid

do polyesters hydrolyse easier with an acid or a base?

• with a base

carboxyl groups react with amino groups to form what links?

• amide links -CONH- forming a polyamide

carboxyl groups react with hydroxyl groups to form what links ?

• -COO- forming a polyester

what does a polyamide react with water to produce?

• a dicarboxylic acid and a diamine

what do polyesters react with a base to produce?

• a dicarboxylic salt and a diol