Q. The precipitate of $Fe(OH)_{3}$ in presence of water containing some ${FeCl}_{3}$ becomes colloidal on gentle shaking. This is an example of
A) Electroosmosis
B) Coagulation
C) Peptization
D) Electrophoresis
Explanation
(c)
When some FeCl_{3} is added to the Fe(OH)_{3} solution, Fe^{3+} ions are preferentially adsorbed on $Fe(OH)_{3}$ particle. Thus, it turns into positive ferric hydroxide sol$\left\lbrack Fe(OH)_{3} \right\rbrack{Fe}^{3 +}.$ This process is called peptisation.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.