JEE Main202126 Feb 2021Evening ShiftChemistrySurface ChemistryActual
The nature of charge on resulting colloidal particles when FeCl 3 is added to excess of hot water is:
Options
- Apositive
- Bsometimes positive and sometimes negative
- Cneutral
- Dnegative
Correct answer
A. positive
Step-by-step solution
If FeCl 3 is added to hot water, a positively charged sol, hydrated ferric oxide is formed due to adsorption of Fe 3 + ions. Fe 2 O 3 · xH 2 O / Fe 3 + Positively charged. Thus, When   FeCl 3 ​ sol is treated with hot water, it forms Fe ( OH ) 3 ​ forming Fe 3 + ions(in excess amount) and these positive ions are adsorbed preferentially.