Question

20 mL of 0.5 M NaCl is required to coagulate 200 mL of As2S3 solution in 2 hours. The coagulating value of NaCl is____

Hint:

Coagulating value is inversely proportional to the coagulating power of an electrolyte

Answer 1

Correct Answer: 50

Coagulating Value Calculation

Definition: The coagulating value is defined as the amount of electrolyte (in millimoles) required to coagulate 1L of colloidal solution in 2 hours.

Calculation

1. Moles of NaCl used:

Moles = M × V = 0.5 × 20 mL = 10 mmol

1. Coagulating Value:

Coagulating Value = 10 200 × 1000 = 50 

Final Answer

The coagulating value is 50.