Gold number of hemoglobin is 0.03. Hence,1OO mL of gold sol will require how many mg hemoglobin so that gold is not coagulated by 1 mf of 10% NaCl solution?

The gold number is the amount of protective colloid in milligrammes that prevents 10 milliliters of red gold sol from coagulating when 1 milliliter of a sodium chloride solution is introduced to it.

Hb's gold number in this case is 0.03.

Therefore, 0.03 mg of Hb is needed for 10 ml of gold.

So, 0.30mg of gold is needed to make 100 ml of solution.