(a) Under which category of mixtures will you classify alloys and why?
(b) A solution is always a liquid. Comment.
(c) Can a solution be heterogeneous?

Explanation

(a) Alloys are homogeneous mixtures of metals, because
(i) it shows the properties of its constituents, and
(ii) it has variable composition., e.g., brass is considered a mixture, because it shows the properties of its constituents, copper and zinc, and it has a variable composition (amount of Zn in brass can vary from 20 to 35 per cent).
(b) A solution is generally a liquid, not always. It may involve solids and gases also, e.g., alloys are solution of solid. Air is solution of gases in gases.
(c) Colloidal solution are heterogeneous in nature, though they appear to be homogeneous.