Question

On adding $FeC{l}_3$ solution into NaOH solution, a positively charged colloidal sol is obtained when they are in :

• A. 100 mL of 0.1 M FeCl₃ + 50 mL of 0.1M NaOH
• B. 50 mL of 0.1 M FeCl₃ + 200 mL of 0.1M NaOH
• C. 10 mL of 0.1 M FeCl₃ + 50 mL of 0.1M NaOH
• D. 200 mL of 0.1 M FeCl₃ + 800 mL of 0.1M NaOH

Answer 1

The correct option is A

100 mL of 0.1 M FeCl₃ + 50 mL of 0.1M NaOH

Since the ppt is $Fe(OH{)}_3,F{e}^{+3}$ ion must be in excesses to get positively charged colloid