250+ TOP MCQs on Desulfonation Reactions and Answers

Unit Processes Multiple Choice Questions on “Desulfonation Reactions”.

1. Hydrolytically sulfonated is reacted in which medium?
a) Aqueous basic medium
b) Aq. Acidic medium
c) Neutral medium
d) None of the mentioned
Answer: b
Clarification: Aromatic sulfonates are hydrolytically desulfonated by heating in aqueous acid medium.

2. Which type of reaction is the following: RSO₃H + HOH ——> RH + H₂SO₄.
a) Sulfonation
b) Desulfonation
c) Chlorosulfonation
d) Rearrangement
Answer: b
Clarification: The following reaction is Desulfonation of Aromatic sulfates.

3. What effect does Mineral acid has on Desulfonation reaction?
a) Increases reaction rate
b) Decrease reaction rate
c) No effect on it
d) Inhibits the reaction
Answer: a
Clarification: Desulfonation reaction, which is the reverse of sulfonation, generally proceeds rapidly and in good yield, especially in the presence of an added mineral.

4. Which of the following is/are mineral acid?
a) Phosphoric
b) Hydrochloric
c) Hydrobromic
d) All of the mentioned
Answer: d
Clarification: Sulfuric, phosphoric, hydrochloric, hydrobromic comes under Mineral acids.

5. What effect does increased ring methylation has on Sulfonation?
a) Increases
b) Decreases
c) Neutral
d) None of the mentioned
Answer: a
Clarification: It is known that increased ring methylation generally lowers the desulfonation temperature for both hydrocarbon and phenolic sulfonates.

6. Sulfonation, followed by desulfonation method cannot be used for separation of Aromatic compounds.
a) True
b) False
Answer: b
Clarification: Sulfonation, followed by desulfonation, has been used to separate mixtures of aromatic compounds not easily separable by distillation. Either or both steps can be selective.

7. Sulfonation-Desulfonation is useful in preparation of what?
a) Ortho isomer
b) Para isomer
c) Meta isomer
d) None of the mentioned
Answer: a
Clarification: Sulfonation-desulfonation is a useful tool for preparing ortho isomer derivatives of benzene.

8. Why is there a need to use “Brining-out” process?
a) Mixing Sulfonates
b) Increasing reaction
c) Isolating sulfonates
d) All of the mentioned
Answer: c
Clarification: The “brining-out” procedure is used commercially to isolate many sulfonate dye intermediates, including those from nitrobenzene, the nitrotoluenes, the nitro chlorobenzenes, naphthalene etc.