6.2 nitrogen compounds, polymers and synthesis Flashcards
What are amines
They are a class of compounds related to ammonia NH3
They are organic chemicals where one or more of the hydrogen atoms on ammonia have been replaced by alkyl chains
What are teh3 types of amine
primary - one hydrogen atom has been substituted RNH2
secondary - 2 hydrogen atoms have been substituted RNHR
tertiary - All three hydrogen atoms have been substituted RNR’R’’
How would you name a primary amine
adding the suffix amine
How would you name secondary amines
write the alkyl chains in alphabetical order and add the suffix amine
Secondary amines are often called N-substituted and is given as a prefix to the name
N-methyl propylamine
How would you name tertiary amines
name the alkyl chains in alphabetical order and add suffix
the prefix is N.N-
N,N-diethyl propylamine
define lewis base
has a lone pair of electrons for donation
Define Bronsted-Lowry base
A proton acceptor
How does an amine act as a lewis base
ammonia and amines have a lone pair of electrons on the nitrogen atom that they are able to donate mking them a lewis base
How do amines act as Bronsted-Lowry bases
Ammonia and amines can accept protons on the nitrogen atom
Describe the reaction between an amine and dilute inorganic acid
An alkylammonium salt is made and this is formed by the proton in the acid being replaced by an alkyl ammonium ion
give the symbol equation for the reaction of ethylamine with hydrochloric acid
CH3CH2NH2 +HCl → CH3CH2NH3+ +Cl- Ethyl ammonium chloride
How do you prepare amines
Heat in a sealed tube but not reflux as it is too volatile
heat the haloalkane with ammonia and ethanol
How do you prepare aromatic amines
Heat under reflux nitrobenzene with tin and conc. HCl which acts as the reducing agent at 100C
After about half an hour a strong alkali is added which undergoes a neutralisation reaction to remove excess hydrochloric acid and produce the amine
Producing aromatic amines is a multi-stage process that includes steam distillation solvent extraction and futher distillation
Give the equation for the reduction of nitrobenzene
nitrobenzene +6[H] → phenylamine +2H2O
Give the stricture of an amino acid
RCH(NH2)COOH
Describe the properties of an amino acid
it is a weak acid that will partially ionise in water
The nitrogen has a lone pair of electrons so it can act as a base meaning amino acids are amphoteric
Define zwitterion
an internal salt with no charge formed by the donation of a proton from a carboxylic acid funtional group to the amine functional group
What is the isoelectric point
when there is no net charge due to the zwitterion having an internal balance of charge
What happens to an amino acid at a low pH
The amino acid is acting as a base and accept a proton from the acid
the carboxylic acid functional group becomes COOH and the NH2 group becomes charged NH3
What happens to an amino acid at a high pH
The amino acid is acting as an acid and donates a proton to the hydroxide ion
The NH2 group remains the same while the carboxylic acid group becomes the charged COO-
Describe the reaction between an amino acid and a metal oxide
It is a neutralisation reaction so it will react with the carboxylic acid to form a metal salt and water
Describe the reaction between an amino acid and an alkali
It is a neutralisation reaction so it will react with the carboxylic acid to form a salt and water
Describe the reaction between an amino acid and carbonate
It is a neutralisation reaction so it will react with the carboxylic acid to form a salt, co2 and water
Describe the reaction between an amino acid and alcohol
Will produce an ester and water
