6.1.3 Carboxylic Acids and Esters Flashcards
(25 cards)
What is the functional group of a carboxylic acid?
COOH (C=O and C-OH)
How do you name carboxylic acids?
-oic acids
Are carboxylic acids soluble in water? Why?
Yes. Acid group can form hydrogen bonds with water molecules
What are the intermolecular forces in carboxylic acids?
Hydrogen bonds in solid state- very strong
What are esters? Functional group, general formula?
Formed from carboxylic acids and alcohols. RCOOR’ (C=O, C-O-C)
How do you name esters?
Start with the alcohol group that has replaced the hydrogen, then acid part e.g propyl (from alcohol) ethanoate (from carboxylic acid)
What characteristic physical properties do esters have?
Volatile, pleasant fruity smells e.g. apple, pear drops
What are some uses of esters?
Flavourings, perfumes (both for longer chains), solvents (short chains), plasticisers
How would you distinguish carboxylic acids from other -OH containing compounds?
Add NaHCO3, acids will produce sodium salt, water and carbon dioxide
Write an equation for reaction of ethanoic acid with NaOH
CH3COOH + NaOH -> H2O + CH3COO-Na+
Write an equation for reaction of ethanoic acid with Na2CO3
2CH3COOH + Na2CO3 -> 2CH3COO-Na+ + H2O + CO2
Write equation for reaction of ethanoic acid with calcium oxide
2CH3COOH + CaO -> (CH3COO)2Ca + H2O
What catalyst is needed for formation of esters from alcohols and carboxylic acids?
Concentrated strong acid e.g. H2SO4
What catalyst is needed for hydrolysis of esters?
Dilute strong acid e.g. H2SO4
What is an alternative method of hydrolysis?
Base hydrolysis
What are advantages of base hydrolysis?
Reaction goes to completion due to neutralisation by base- more product in the mixture than acid catalysed hydrolysis
What are carboxylic acid derivatives?
Molecules that have the acyl group as part of their structure, formed from carboxylic acids
Name two acid derivatives and give their functional groups.
Acyl chlorides: RCOCl
Acid anhydrides: RCOOCR/ (RCO)2O
How do you form an acyl chloride?
React a carboxylic acids with SOCl2
If nucleophile is ammonia for acylation of acyl chlorides or acid anhydrides, what are the products of the reaction?
An amide
Write an equation for reaction of ethanoyl chloride and ammonia
CH3COCl + 2NH3 -> CH3CONH2 + NH4Cl
If the nucleophile is a primary amine, what are the products of the acylation of acyl chlorides or acid anhydrides?
N-substituted amide
If the nucleophile is an alcohol, what are the products of the acylation of acyl chlorides or acid anhydrides?
An ester
If the nucleophile is water, what are the products of the acylation of acyl chlorides or acid anhydrides?
Carboxylic acid (hydrolysis produces an ester linkage)
