Question

Identify the solutions among the following mixtures.
A. Soil
B. Sea water
C. Air
D. Coal
E. Soda water

Answer 1

Hint: Classify given materials as homogeneous and heterogeneous. Homogenous mixtures contain a uniform composition throughout.

Complete step by step answer:
A solution is a homogeneous mixture of two or more components. The particle size is less than 1 nm. These particles cannot be seen with a microscope. Particles of solution pass through filter paper. Only one phase is present in homogeneous mixtures. Homogeneous mixture is uniform throughout and one part cannot be distinguished from the other part.
Sea water, air and soda water are homogeneous mixtures and they are classified as solutions. Sea water is a homogeneous mixture of various minerals and salts in water. Air is a homogeneous mixture of nitrogen, oxygen and several other gases. Only one phase (gaseous state) is present in air. Soda water is a homogeneous mixture of carbon dioxide gas dissolved in water. Carbon dioxide gas is uniformly distributed in water and its concentration is the same throughout.

Coal and soil are heterogeneous mixtures and they cannot be classified as solutions.

Hence, (b), (c) and (e)are correct answers.

Note:
Although coal and soil appear as one phase but they cannot be classified as solutions because their composition is not uniform throughout.