Comment on the statement that `"` colloid is not a substance but state of a substance `"`

Explanation

Colloid is not a substance but it is a state of substance. This statement means a particular substance may exist as a colloid unuer certain conditions and as a crystalloid under other conditions. For example, sodium chloride in water behaves as a crystalloid while in benzene, it behaves as a colloid. Similarly, dilute soap solution behaves like a crystalloid while the concentrated solution behaves as a colloid (called associated colloid). It is the size of the particle that decides the state in which the substance exists. If the size of the particles lies in the range of 10 nm to 100 nm, it is in the colloidal state.