Question

Coagulation of 90 ml of a negative sol requires 10 ml of 0.5 nacl. The coagulation value of nacl is

Answer 1

Explanation : Coagulation value is the millimoles of an electrolyte that must be added to 1 L of a colloidal solution for complete coagulation . Therefore , 5 mL of 1 M NaCl = 11000×5=0.005 or 5 m moles .

Answer 2

Given: 90mL of a negative sol, it requires 10 mL of 0.5M NaCl.

To find: the coagulation value of NaCl.

Step-by-step method:

Step 1 of 2

The number of mmoles in 10 mL of 0.5M NaCl are:

$moles=Molarity*Volume\\moles=0.5*10\\moles=5mmol$

Step 2 of 2

90 mL of negative sol requires the mmoles of NaCl for coagulation = 5mmol.

1000 mL of negative sol requires the mmoles of NaCl for coagulation = $\frac{5*1000}{90}=55.5mmol$

90mL of negative sol requires 55.5mmol of NaCl.

The coagulation value of NaCl is 55.5.