250+ TOP MCQs on Natural Products – Soaps and Answers

Chemical Process Technology Multiple Choice Questions on “Natural Products – Soaps”.

1. What is the purpose of adding cleansing agent?
a) Increase wet ability and decrease surface tension
b) Decrease wet ability and increase surface tension
c) Decrease wet ability
d) Increase surface tension

Answer: a
Clarification: Cleansing agent provides hydrophilic and hydrophobic groups which are responsible for increase in wetting ability and decreasing the surface tension.

2. Which of the following represents saponification process reaction? M represents an alkali metal.
a) R-COOH+ M-OH→ M-COOR + H₂O
b) M-COOH +R-OH → R-COOM + H₂O
c) R-COOH+ M-OH → R-COOM + H₂O
d) M-COOH + R-OH → M-COOR + H₂O

Answer: c
Clarification: Saponification is a process used for the production of soap. As soap is formed by conversion of fat into a fatty acid on reacting with alkali, the correct reaction is c. Fatty acid R-COOH reacts with an alkali M-OH to produce soap R-COOM and water H₂O.

3. Fat splitting reaction of soap manufacture takes place in ______________
a) blender
b) hydrolysis tower
c) mixer
d) high vacuum still

Answer: b
Clarification: Triglycerides and catalyst are added at the bottom of hydrolysis tower, where the fat splitting reaction takes place with counter current passage of high pressure water and removal of 15-20% glycerin solution.

4. Why a Flash tank is used in soap manufacturing unit?
a) To remove impurities
b) To add alkali
c) To add excess steam
d) To remove excess steam

Answer: d
Clarification: The fatty acids produced in the hydrolysis tower are sent into a flash tank where the removal of excess steam takes place. Then the crude fatty acids are sent into vacuum still for further operations.

5. Where does saponification takes place in continuous process?
a) Hydrolysis tower
b) Blender
c) Vacuum still
d) Mixer

Answer: b
Clarification: Vacuum distilled fatty acids are sent into mixer where caustic soda is added, and then the saponification process takes place in a slow speed blender.

6. What are the operating conditions of hydrolysis tower?
a) 230-250° C and 40-45 atm
b) 200-220° C and 40-45 atm
c) 180-230° C and 20-30 atm
d) 230-250° C and 20-30 atm

Answer: a
Clarification: Triglycerides, catalyst are added at bottom of hydrolysis tank with addition of high pressure water at 230-250° C and 40-45 atm.

7. Soaps are sodium salts of alkylated fatty acids.
a) False
b) True

Answer: a
Clarification: The statement is false since soaps are sodium/potassium salts of fatty acids. Hence they are formed from fats and alkali.

8. Which of the following indicates continuous process for soaps?
a) Hydrolysis tower, mixer, blender, vacuum still
b) Vacuum still, hydrolysis tower, mixer and blender
c) Hydrolysis tower, blender, mixer, vacuum still
d) Hydrolysis tower, vacuum still, mixer, blender

Answer: d
Clarification: Raw materials are sent into hydrolysis tower where fat splitting reaction takes place, and then the crude fatty acids are passed through vacuum still and through mixer where addition of NaOH takes place, finally through blender for saponification to take place.

9. Which one of the following additive converts yellow glycerin into sweet water?
a) Potash
b) Detergent builders
c) Activated charcoal
d) Caustic soda

Answer: c
Clarification: Yellow glycerin produced from 15-20% glycerin solution when absorbed with activated charcoal, followed by filtration gives 99% white glycerin also called as sweet water.

10. What is the important byproduct of soap manufacture unit?
a) Fatty acid product
b) Glycerin
c) Glycosides
d) Caustic soda

Answer: b
Clarification: Glycerin is the important byproduct of soap manufacture. The removed 15-20% glycerin is sent into triple effect evaporator for the production of yellow glycerin.