Question

Lump of cotton shrink in water because

• A. Air present in lump of cotton is replaced by water which occupies less space.
• B. Air doesn't occupy space but water does.
• C. Space occupied by water is more than that of the space occupied by air.
• D. Water does not occupy any space.

Answer 1

Answer: (A)

The explanation for the correct option:

Option(B) Air present in a lump of cotton is replaced by water which occupies less space.

• A lump of cotton is porous, it has air trapped inside the space present between its fibers.
• When it is dissolved in water, water removes the air and occupies the space that was occupied by air and thus cotton lump becomes heavy and also shrinks down.

The explanation for the incorrect option:

(A) Water does not occupy any space.- water does occupy space, it has a definite volume.

(C) Space occupied by water is more than that of the space occupied by air.- it's a wrong statement because air has the ability to expand, so the volume of air is indefinite, hence the Space occupied by air is more than that of the space occupied by water.

(D) Air doesn't occupy space but water does.- Both of them occupy space.

Hence, Option(B) Air present in a lump of cotton is replaced by water which occupies less space is the reason for Lump of cotton shrink in water