Question

What are the reagents used to rectify ``over-bluing'' in white cotton fabrics?

• A. Dilute acid solution
• B. Dilute alkali solution
• C. Hydrogen peroxide
• D. Sodium chloride solution

Hint:

{Over-bluing} in white fabrics can be corrected by rinsing the fabric with a {dilute acid solution} to remove excess blue dye.

Answer 1

The Correct Option is A

Concept: Bluing is a finishing process used in laundering white fabrics to counteract yellowing and enhance the appearance of whiteness. A small amount of blue dye is added so that the fabric appears brighter. However, if too much blue is applied, the fabric may develop a bluish tint, which is referred to as over-bluing.
Step 1: Understand over-bluing.
Over-bluing occurs when excess blue dye remains on the fabric during the laundering process, giving the fabric an undesirable blue shade.
Step 2: Method of rectification.
To remove the excess blue dye, the fabric is rinsed in a dilute acid solution such as diluted acetic acid. The acid helps neutralize and remove the extra bluing from the fabric.
Step 3: Conclusion.
Therefore, the reagent used to correct over-bluing in white cotton fabrics is: \[ \text{Dilute acid solution} \]