250+ TOP MCQs on C3 Compounds – Isopropanol and Answers

Chemical Technology Multiple Choice Questions on “C3 Compounds – Isopropanol”.

1. How is industrial isopropanol manufactured?
a) Hydration of propylene
b) Fermentation of molasses
c) Contact process
d) Linde’s process

Answer: a
Clarification: Isopropanol is manufactured by the hydrolysis of propylene. Propylene is absorbed in a tray tower filled with sulfuric acid to produce isopropyl acid sulphate. Ethanol is manufactured by fermentation of molasses. Oxygen is manufactured by Linde’s process whereas sulfuric acid is manufactured by contact process.

2. Which compound is used to decrease the temperature in the absorber during the manufacture of isopropanol by hydration of propylene?
a) Refrigerated brine
b) Cold water
c) Sulphuric acid
d) Nitric acid

Answer: a
Clarification: Refrigerated brine is used to control the temperature in the absorber. Jacketed arrangement is used in order to circulate the refrigerated brine in the cooling jacket. Brine is used since it has an ability to reach low temperatures without freezing problem.

3. How do we remove the presence of acidic impurities in the manufacture of isopropanol?
a) Wash water
b) Caustic wash
c) Sulphuric acid
d) Phosphoric acid

Answer: b
Clarification: The isopropanol vapours consists acidic impurities which can be removed with the help of a caustic wash tower. Caustic wash generally consists of caustic soda. Sulphuric acid is used as an absorber in hydration of propylene.

4. Acetone can be prepared from isopropanol. True or false.
a) True
b) False

Answer: a
Clarification: IPA (Isopropanol) is used as an intermediate for the preparation of acetone. One phenol process gives acetone as co product.

5. What is the by product produced in the manufacture of isopropyl alcohol by indirect hydration of propylene?
a) Isopropanol
b) Isopropyl ether
c) Acetic acid
b) Fumaric acid

Answer: b
Clarification: In the manufacture of isopropanol propylene is sulphated to produce isopropyl acid sulphate which on hydrolysis produces diiospropyl sulphate which finally produces isopropyl ether as a by-product.