Carboxylic acids Flashcards
1
Q
Describe a carboxylic acid
A
- a carboxyl group contains both a carbonyl group and a hydroxyl group
2
Q
How do u name a carboxylic acid?
A
- the suffix -oic is added to the stem of the longest carbon chain
- the carboxyl carbon atom is always designated as carbon 1
3
Q
Why are carboxylic acids soluble in water?
A
- carboxylic acids are soluble in water as the C=O bond and O-H are polar so therefore carboxylic acids can form hydrogen bonds with water
4
Q
What affects the solubility of carboxylic acids
A
- As chain length increases, solubility decreases as the non - polar chain has a greater influence of the solubility of the carboxylic acids
- as the number of carboxyl groups increases, solubility increases as more hydrogen bonds can form with water
5
Q
Draw a diagram of hydrogen bonding of carboxylic acids and water
A
- 2 lone pairs on oxygen
- the O—–H —– O should be 180 degrees
- each atom should have an electronegative or positive charge
- hydrogen = electropositive
- carbon and oxygen = electronegative
6
Q
What are the neutralisation reactions carboxylic acids can undergo
A
- metal oxides
- alkalis
- metal carbonates
7
Q
What is the reaction of carboxylic acids and metal oxides?
A
- it forms a salt and water
- 2CH3COOH (aq)+ CaO(s) = (CH3COO-)2 Ca2+ (aq) + H20 (l)
8
Q
What is the reaction of alkalis and carboxylic acids
A
- it forms a salt and water
- CH3COOH + NaOH = CH3COO - NA+ + H20
9
Q
What is the reaction of metal carbonates and carboxylic acids
A
- it forms a salt, water and carbon dioxide
- 2CH3COOH + Na2CO3 = 2CH3COO- NA+ + CO2 + H20
10
Q
What is the test for the carboxyl group?
A
- The neutralisation reaction with carbonates produces co2 and effevesence and allows carboxylic acids to be distinguished
