Question

What is cellophane?

• A. Regenerated cellulose
• B. Cellulose combined with ethane
• C. Cellulose combined with methane
• D. Carboxy methyl cellulose

Hint:

"Regenerated" means the chemical was broken down and then "re-born" into a new physical shape (from fibers to a film).

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
The question asks for the chemical identity of cellophane, a thin, transparent sheet material commonly used for food packaging.

Step 2: Detailed Explanation:

• Composition: Cellophane is a polymer manufactured from cellulose. Cellulose is a natural polysaccharide found in the cell walls of plants (typically derived from wood, cotton, or hemp).

• Manufacturing Process (Viscose Process): To make cellophane, cellulose is dissolved in an alkali and carbon disulfide to create a solution called "viscose." This viscose is then extruded through a slit into a bath of dilute sulfuric acid and sodium sulfate.

• Regeneration: The acid bath "regenerates" the cellulose, turning the liquid viscose back into a solid, transparent film. This is why it is technically called "Regenerated Cellulose."

• Properties: It is highly permeable to water vapor (unless coated) but provides an excellent barrier to air, oils, and bacteria. It is also biodegradable, unlike most plastic films.
• Difference from Carboxymethyl Cellulose (CMC): CMC is a chemical derivative of cellulose used as a thickener and stabilizer in foods, not a packaging film. Cellophane involves changing the physical form of cellulose through a chemical dissolution and precipitation process.

Step 3: Final Answer: Cellophane is scientifically defined as regenerated cellulose.