Benzoic acid and carbolic acid can be distinguished By:

Question

Benzoic acid and carbolic acid can be distinguished By: (A) Aqueous NaHCO 3 (B) Neutral FeCl3 (C) Aqueous NaOH (D) Aqueous NH 3

Tardigrade Admin · Accepted Answer

a. Phenol is also called carbolic acid
Benzoic acid is more acidic than phenol. So the acid reacts with

N a H C O_{3}

to give

C O_{2} (g)

, while phenol does not react
b. Acids give buff-coloured precipitate with neutral

F e C l_{3}

, while phenol gives violet colouration with neutral

F e C l_{3}

solution, e.g.,

3 P h COO H + F e C l_{3} \to (P h COO)_{3} F e + 3 H Cl

(Ferric benzoate)(Buff coloured ppt.)

3 P h O H + F e C l_{3} \to (P h O)_{3} F e + 3 H Cl

(Ferric Phenoxide)(Violet colouration)
c. Both acid and phenol react with aqueous

N a O H

to give their corresponding salts

P h COO H + N a O H \to P h COON a

P h O H + N a O H \to P h ON a

d. Both acid and phenol react with

N H_{3}

P h COO H + N H_{3} \to P h CON H_{2}

(Benzamide)

+ H_{2} O

P h O H + N H_{3} \to P h N H_{2}

(Aniline)

+ H_{2} O

So the answers are (a) and (b)

Q. Benzoic acid and carbolic acid can be distinguished By: