Question

Which one of the following electrolytes is most effective for the coagulation of $Fe(OH)_3$ sol?

• A. NaCl
• B. Na$_2$SO$_4$
• C. Na$_3$PO$_4$
• D. As$_2$S$_3$

Hint:

When selecting electrolytes for coagulation, choose those with more charged ions as they more effectively neutralize the sol particles.

Answer 1

The Correct Option is C

The coagulation of $Fe(OH)_3$ sol is most effectively achieved by electrolytes that can provide a large number of ions. Na$_3$PO$_4$ is a more effective coagulating agent because the phosphate ions can interact strongly with the positively charged $Fe(OH)_3$ sol particles, causing them to aggregate and settle.