Question

Give the correct sequence of manufacturing viscose rayon.
A. Ageing
B. Xanthating
C. Shredding
D. Steeping
E. Filtering
F. Dissolving
G. Spinning
Choose the correct answer from the options given below:

• A. A, B, C, D, F, E, G
• B. C, A, B, D, E, G, F
• C. D, C, A, B, F, E, G
• D. C, D, A, E, F, G, B

Hint:

Remember the viscose rayon process:
"D. Steeping, C. Shredding, A. Ageing, B. Xanthating, F. Dissolving, E. Filtering, G. Spinning"
Use the mnemonic: "Dry Cats And Xyz Find Easy Games"
- Steeping (D)
- Shredding (C)
- Ageing (A)
- Xanthating (B)
- Dissolving (F)
- Filtering (E)
- Spinning (G)

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
This question tests knowledge of the manufacturing process of viscose rayon, a regenerated cellulosic fiber.

Step 2: Detailed Explanation:
Steeping (D):
First step - Wood pulp (cellulose) is treated with sodium hydroxide (caustic soda) to form alkali cellulose.
This is the initial chemical treatment.
Shredding (C):
Second step - The alkali cellulose is shredded into small crumbs to increase surface area.
This makes it easier for subsequent chemical reactions.
Ageing (A):
Third step - The shredded alkali cellulose is allowed to stand for 2-3 days.
This process reduces the degree of polymerization of cellulose.
Xanthating (B):
Fourth step - The aged alkali cellulose is treated with carbon disulfide.
This forms cellulose xanthate, which is soluble in sodium hydroxide.
Dissolving (F):
Fifth step - The xanthate is dissolved in dilute sodium hydroxide to form a viscous solution.
This is called "viscose" (hence the name).
Filtering (E):
Sixth step - The viscose solution is filtered to remove undissolved particles.
This ensures a smooth and uniform fiber.
Spinning (G):
Seventh step - The filtered viscose is extruded through spinnerets into a coagulating bath.
This regenerates cellulose fibers, which are then drawn, washed, and dried.

Step 3: Final Answer:
Thus, the correct sequence is D, C, A, B, F, E, G, which corresponds to option (C).
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