question_answer 35)

Comment on the statement that “colloid is nota substance but a state of substance”.

Answer:

All substances (soluble or insoluble) can be made to behave as colloids under suitable conditions. For example, sodium chloride in water forms a true solution but in benzene it forms a colloidal solution. Similarly, soap behaves as a colloid in aqueous solution and as crystalloid in alcohol.Thus, colloids do not form a separate class of substances, it is rather a state of sub-division of matter called colloidal state (particles having diameter ranging from 1 nm to 100 nm) just as a substance may exist in solid, liquid or gaseous state under different conditions.