Colloids among the following that cannot be coagulated easily is -

a.  Lyophobic colloids

b.  Irreversible colloids

c. Reversible colloids

d.  Lyophilic colloids


1. (a, b)
2. (b, c)
3. (c, d)
4. (a, d)

Hint: Reversible sols are quite stable and cannot be easily coagulated
 
Lyophilic colloids (liquid loving colloicls) which are also known as reversible colloid can't be coagulated easily. The stabilily of these colloids are due to
(i) Charge on colloidal particies and

(ii) Solvation of colloidal parlicle