Question

Which of the following acts as the best coagulating agent for ferric hydroxide sol?

• A. (a) Potassium ferrocyanide
• A. (b) Potassium chloride
• A. (c) Potassium oxalate
• A. (d) Aluminium chloride

Answer 1

(a)

Sol. The efficiency of coagulations of an electrolyte depends upon its valency. Thus $\left[ \mathrm { Fe } ( \mathrm { CN } ) _ { 6 } \right] ^ { 4 - }$is the best coagulating agent for $\mathrm { Fe } ( \mathrm { OH } ) _ { 3 }$ sol.