Question

The coagulation of $200mL$ of a positive colloid took place when $0.73g$ $HCl$ was added to it. The flocculation value of $HCl$ for the colloid is:

• A. $150$
• B. $200$
• C. $100$
• D. $36.5$

Answer 1

The correct option is C $100$

Number of moles of $HCl$ added $=\frac{0.73}{36.5}=0.02mol=20mmol$
Thus, number of millimoles required by $1000ml$ sol
$=\frac{20}{200}\times 1000=100mmol$