Question

For the coagulation of $500$ mL of arsenious sulphide sol, $2$ mL of $1M$ $NaCl$ is required. What is the flocculation value of $NaCl$?

• A. $3$
• B. $2$
• C. $5$
• D. $4$

Answer 1

Answer: (A), (D)

$3$
$4$

The minimum amount of an electrolyte required to cause precipitation of one litre of a colloidal solution is called coagulation value or flocculation value of the electrolyte for the sol.
For the coagulation of $500$ mL of arsenious sulphide sol, $2mL$ of $1M$ $NaCl$ is required. For the coagulation of $500mL$ of arsenious sulphide sol, $4$ mL of $1M$ $NaCl$ will be required.
The flocculation value of $NaCl$ is $4$.