# The coagulation of 200 mL of a positive colloid took place when 0.73 g HCl was added to it without changing the volume much. The flocculation value of HCl for the colloid is

(a) 0.365
(b) 36.5
(c) 100
(d) 150

200 mL of the sol needs = $\large\frac{0.73}{36.5 g/mol}$ = 0.02 mol = 20 m mol
1000 mL of the sol needs = $\large \frac{20 \times 1000}{200}$ = 100 m mol
$\therefore$ flocculation value of HCl for the colloid is 100.
edited Mar 23, 2014