Carboxylic acids and their reactions

Question 1

Why are carboxylic acids the most acidic?

Answer 1

The carboxylate ion has lower electron density because the negative charge is spread all over the ion. This makes the carboxylate ion more stable and so the H+ concentration is highest and the acidity is highest in carboxylic acids.

Question 2

5 reactions of carboxylic acids (oxidations and acyl chlorides productions):

Answer 2

1. Oxidation of methanoic acid.
2. Oxidation of ethanedioic acid.
3. C.Acid + PCl₃(l)
4. C.Acid + PCl₅(s)
5. C.Acid + SOCl₂(l)

Question 3

Carboxylic acids cannot get oxidised except:

Answer 3

Methanoic acid and Ethanedioic acid.

Question 4

Oxidation of methanoic acid (REAGENTS AND PRODUCTS)

Answer 4

REAGENTS= Methanoic acid + Tollen’s or Fehling’s reagent or Warm acidified KMnO₄ (VII) or K₂Cr₂O₇ (VI).
STRONG OR MILD OXIDISING AGENTS CAN BE USED.
PRODUCTS= CO₂ and H₂O.

Question 5

Methanoic acid is a strong…

Answer 5

Reducing agent.

Question 6

Oxidation of ethanedioic acid (REAGENTS AND PRODUCTS)

Answer 6

REAGENTS= Ethanedioic acid + Warm acidified KMnO₄ (VII) or K₂Cr₂O₇ (VI).
STRONG OXIDISING AGENTS ONLY.
PRODUCTS= CO₂ and H₂O.

Question 7

Ethanoic acid + PCl₃(l) —>
EQUATION AND CONDITION

Answer 7

Ethanoic acid + PCl₃(l) —> Ethanoyl chloride + H₃PO₃
CONDITION= HEAT.

Question 8

Ethanoic acid + PCl₅(s) —>
EQUATION AND CONDITION

Answer 8

Ethanoic acid + PCl₅(s) —> Ethanoyl chloride + POCl₃ + HCl
CONDITION= NO OTHER CONDITION

Question 9

Ethanoic acid + SOCl₂(l) —>
EQUATION AND CONDITION

Answer 9

Ethanoic acid + SOCl₂(l) —> Ethanoyl chloride + SO₂ + HCl
CONDITION= NO OTHER CONDITION