Carboxylic Acids
Carboxylic acid is the name given to the family of compounds
containing the carboxyl functional group ( COOH ). The general
formula is C (n) H (2n + 1) COOH or RCOOH.
Weak Acids
Carboxylic Acids with fewer than 6 Carbon atoms per molecule are
water soluble due to hydrogen bonding bet ween the functional
group and the water molecule.
In aqueous solutions they are only slightly ionised, to give low
concentrations of hydronium ions ( H3O+ ) and alkanoate ions
( carboxylate ions ). For example:
This partial ionisation means that carboxylic acids are weak acids.
The position of equilibrium lies to the left and that the
concentration of H+ is much smaller than the concentration of the
carboxylic acid. However, the concentration of H+ is suf cient to
react with an aqueous solution of sodium carbonate or sodium
hydrogencarbonate to liberate/produce CO2. This would be visible
via zzing/ bubbles in the mixture. For Example :
2CH3COOH (aq) + Na2CO3 (s) ==== 2CH3COONa (aq) + H2O (l) + CO2 (g)
Ethanoic Acid + Sodium Carbonate = Sodium Ethanoate + Water + CO2
, This is the reaction for carboxylic acids with carbonates. However
carboxylic acids reacting with hydroxides give the sodium salt
and water only.
Esters
Esters are organic compounds that contain a COO group.
They are produced by esteri cation reactions which are an example
of nucleophilic addition/elimination. The carboxylic acid reacts
with an alcohol under re ux in the presence of an acid catalyst
( commonly H2SO4 ).
Example: Ethanoic Acid reacting to form Ethyl Ethanoate
Naming Esters:
• Look at the alkyl group that came from the alcohol. This makes
up the rst part of the ester’s name.
• Look at the part that came from the carboxylic acid. Replace
the “-oic acid” for “-oate”
• Put the t wo parts together.
For Example:CH3CH2CH(CH3)COOCH2CH3 The name of this ester is
ethyl 2-methyl butanoate.
Carboxylic acid is the name given to the family of compounds
containing the carboxyl functional group ( COOH ). The general
formula is C (n) H (2n + 1) COOH or RCOOH.
Weak Acids
Carboxylic Acids with fewer than 6 Carbon atoms per molecule are
water soluble due to hydrogen bonding bet ween the functional
group and the water molecule.
In aqueous solutions they are only slightly ionised, to give low
concentrations of hydronium ions ( H3O+ ) and alkanoate ions
( carboxylate ions ). For example:
This partial ionisation means that carboxylic acids are weak acids.
The position of equilibrium lies to the left and that the
concentration of H+ is much smaller than the concentration of the
carboxylic acid. However, the concentration of H+ is suf cient to
react with an aqueous solution of sodium carbonate or sodium
hydrogencarbonate to liberate/produce CO2. This would be visible
via zzing/ bubbles in the mixture. For Example :
2CH3COOH (aq) + Na2CO3 (s) ==== 2CH3COONa (aq) + H2O (l) + CO2 (g)
Ethanoic Acid + Sodium Carbonate = Sodium Ethanoate + Water + CO2
, This is the reaction for carboxylic acids with carbonates. However
carboxylic acids reacting with hydroxides give the sodium salt
and water only.
Esters
Esters are organic compounds that contain a COO group.
They are produced by esteri cation reactions which are an example
of nucleophilic addition/elimination. The carboxylic acid reacts
with an alcohol under re ux in the presence of an acid catalyst
( commonly H2SO4 ).
Example: Ethanoic Acid reacting to form Ethyl Ethanoate
Naming Esters:
• Look at the alkyl group that came from the alcohol. This makes
up the rst part of the ester’s name.
• Look at the part that came from the carboxylic acid. Replace
the “-oic acid” for “-oate”
• Put the t wo parts together.
For Example:CH3CH2CH(CH3)COOCH2CH3 The name of this ester is
ethyl 2-methyl butanoate.
