carboxylic acids and esters Flashcards
Carboxylic acid functional group
COOH
What does a carboxylic acid dissociate to?
Where does the equilibrium lie
RCOO- + H+
To the left - causing more carboxylic acid to be formed
Carboxylic acid + carbonate
Carboxyl salt +co2 + h20
Carboxylic acid + metal
Carboxyl salt + H2
Carboxylic acid + metal oxide
Carboxyl salt + h2o
Carboxylic acid + alkali
Carboxyl salt + H2O
Explain the solubility of carboxylic acids
Polar regions (O &OH) are polar and can form hydrogen bonds with water
Hydrocarbon chain in non polar and cant dissolve in water .
The longer the hydrocarbon chain the less soluble the carboxylic acid
Name 5 ways to make a carboxylic acid
- Oxidising a carbonyl
- Heating an alcohol under reflux
- Acid hydrolysis of a nitrile under reflux
- Acyl chloride + water
- Acid hydrolysis of an ester
Acyl chloride functional group and suffix
-COCl
-oyl chloride
State how to make an Acyl chloride:
include reactants and conditions and reaction name
Carboxylic acid + thionyl chloride –> acyl chloride + sulphur dioxide + HCl
Room temp
Substitution reaction
When an acyl chloride is being made how is it separated from the products
Distillation
Acyl chloride + water
Carboxylic acid + HCl
Acyl chloride + conc ammonia
Primary Amide + HCl
Acyl chloride + alcohol
Ester + HCl
Acyl chloride + Primary amide
N-substituted amides + HCl
Name 3 ways of making an ester and their conditions
- Carboxylic acid + alcohol ⇌ ester + water ( conc h2so4 + less than 60c)
- Acid Anhydride + alcohol -> ester + carboxylic acid (room temp)
- Acyl chloride + alcohol –> ester + HCl
Why is it better to use acid anhydrides or acyl chlorides to make esters rather than carboxylic acids
Both are more reactive and the reaction is irreversible - resulting in a higher yield
How do you name esters
Alcohol = -thyl
acid anhydride/acyl chlorde/carboxylic aicd = -anoate
Whats the functional group of an acid anhydride
(RCO)2O
What’s the order of naming acid anhydrides
Alphabetical order
State the reagents and conditions and products of acid hydrolysis of an ester
Ester + water –> carboxylic acid + alcohol
Reflux
Dilute HCl or H2SO4
State the reagents and conditions and products of Alkali/Base hydrolysis of an ester
Ester + NaOH –> carboxyl salr + alcohol
Reflux
Dilute NaOH
How do you convert a carboxyl salt to a carboxylic acid
Add excess HCl
–> carboxylic acid + compound ( metal chloride)
