9O- Carboxylic Acids And Derivatives Flashcards
What’s the structure of a carboxylic acid
-COOH (functional group)
Consists of a C=O and an -OH group
How to name straight/branched chain carboxylic acids
Alkane name, remove e, oic acid
If there are substitute groups use the C atom in COOH as carbon 1
How to name straight/branched chain carboxylic acids with 2 carboxyl groups
Alkane name, dioic acid (2 carboxyl groups)
How to name carboxylic acids when -COOH is attached to a benzene
Benzenecarboxylic acid
How to name esters
Look at the half of the chain to the side of the C-O bond but without the C=O bond, alkyl name
Count the number of carbons on the other side, alkane name, remove e, oate
Why are carboxylic acids weak acids
The only partially ionise into H+
What is observed when a carboxylic acid is mixed with metal carbonates
Effervescence, produces CO2 gas
What produces esters
Carboxylic acid + alcohol —> ester + water
Conc H2SO4 catalyst
Heat under reflux
Low yield as reaction is reversible
What’s the structure of an ester
C=O bond
O-H is replaced by O-R
Uses of esters
Solvents
Plasticisers
Food flavouring
Perfume
Reaction for hydrolosis of an ester with dilute acid
CH3CH2COOCH2CH3 +H2O —> CH3CH2COOH + CH3CH2OH
Ethyl propanoate + water —> propanoic acid + ethanol
Alkyl—>alcohol
Salt—>acid
Heat under reflux
Dilute H2SO4
Reaction for hydrolosis of an ester with NaOH
CH3CH2COOCH2CH3 +NaOH —> CH3CH2COONa + CH3CH2OH
Ethyl propanoate + sodium hydroxide —> sodium propanoate + ethanol
Heat under reflux
NaOH
Higher yield, carboxylic acid salt is resistant to attack by weak nucleophiles such as alcohols
How to name an ester formed from a 2°/3° alcohol
If alcohol is known take stem and number, replace -ol with -yl
eg propan-2-ol —> propan-2-yl
If ester is known count longest chain up to the C-O bond but without the C=O bond, write like an alkane chain end in -yl, count carbons on other side end in -oate
What’s a fatty acid
Long chain carboxylic acid
What’s the iupac name of glycerol
Propane-1,2,3-triol
What happens when glycerol reacts with a fatty acid
Formation of a fat
What’s a saturated fat
No double bonds in hydrocarbon chain
Unsaturated fat
Contains a double bond in hydrocarbon chain
Reaction to form a triester
CH2OH OH-C=O-R CH2-O-C=O-R
CHOH + OH-C=O-R—> CH-O-C=O-R
CH2OH OH-C=O-R CH2-O-C=O-R
3 H2O molecules are also formed
How is glycerol (propane-1,2,3-triol) used
Cosmetics and food, forms hydrogen bonds easily and is soluble in water
Soap, glycerol forms esters which are hydrolysed in alkaline conditions. Polar CO2- end mixed with water, non polar end mixed with grease allowing it to be washed away
What’s biodiesel
Mixture of methyl esters and long chain carboxylic acids
How is biodiesel produced
Vegetable oils are reacted with methanol
KOH catalyst present
What does acyl chloride/ acid anhydride + alcohol produce
Ester
What does acyl chloride/acid anhydride + primary amine produce
N- sub Amide
N- alkyl name, Alkane name remove e, amide
What does acyl chloride/acid anhydride + water produce
Carboxylic acid
What does acid anhydride/acyl chloride + ammonia produce
Amide (if there’s an oxygen it’s an amide, if there’s no oxygen it’s an amine)
Alkane name remove e, amide
Structure of an amide functional group
R=O
|
NH2
What are industrial advantages of ethanoic anhydride compared to ethanoyl chloride when manufacturing aspirin
Cheaper
Less corrosive
Less vulnerable to hydrolosis
Less dangerous
Test for an acyl chloride
Add a carboxylic acid, white steamy fumes of HCL is given off
Nucleophillic addition elimination of acyl chloride/acid anhydride with nucleophile (water, alcohol, ammonia, primary amine)
Carbonyl bond is polar, s- on oxygen, s+ on carbon, lone pair on nucleophile goes to carbon, arrow from double bond onto oxygen
Oxygen from double bind has lone pair and is -ve, arrow from lone pair to carbon, Oxygen from nucleophile is +ve, arrow from adjacent hydrogen bond onto oxygen, arrow from Cl or RCOO bond goes onto itself
HCL is produced from acyl chlorides
RCOOH is produced from acid anhydrides
