Question

Comment on the statement:

Colloid is not a substance but it is a state of substance.

Answer 1

The statement is true. Because the same substance may exist as a colloid under certain conditions and as a crystalloid under certain other conditions. For example, NaCl in water behaves as a crystalloid, while in benzene, it behaves as a colloid. Similarly, dilute soap solution behaves like a crystalloid, while concentrated solutions behave like a colloid. It is the size of the particles that matters. That is the state in which the substance exists. If the size of the particles lies in the range of 1 nm to 100 nm, it is in the colloidal state.