Question

Which of the following best describes a sol-gel colloidal system?

• A. Butter and milk
• B. Blood
• C. Beaten egg whites
• D. Paper

Answer 1

The correct option is A

Butter and milk

Explanation for correct option:

A. Butter and milk

Colloids:

• “Colloids are heterogeneous mixtures in which the particle size is too small to be seen with the naked eye, but is big enough to scatter light.”
• The particles are called the dispersed phase and the medium in which they are distributed is called the dispersion medium."
• The different types of colloids are aerosols( the dispersed phase is liquid and the dispersion medium is gas), sols(dispersion medium is liquid and the dispersed phase is solid), foam (the dispersed phase is gas and dispersion medium is liquid) as well as gels(liquid is the dispersed phase and solid is the dispersion medium).

Butter and milk are a sol-gel colloidal system in which milk is a sol while butter is a gel type of colloidal system.

Explanation for incorrect options:

B. Blood is a colloidal suspension which means it can behave as a colloid as well as a suspension.

C. Beaten egg whites is a type of foam in which the dispersed phase is gas while the dispersion medium is liquid.

D. Paper is not considered a mixture.

Hence, the correct option is A i.e. Butter and milk.