Discussion Forum



1)

The mass of haemoglobin in mg required to protect from coagulation of 50mL of a gold sol on adding 5mL of 10% NaCl solution is (gold number of haemoglobin=0.03)


A) 0.03

B) 0.75

C) 0.30

D) 0.15

Answer:

Option D

Explanation:

Gold number is the number of milligrams of the protective colloid which prevents the coagulation of 10mL of red gold solution. When 1 mL of a 10 per cent solution of sodium chloride is added to it. Here, gold number of Hb=0.03. So the mass of Hb require for 10 mL of gold is 0.03 mg. So, weight (mass) requires for 50mL of gold solution is 0.15 mg