10^(-4) g of gelatin is required to be added to 100 cm^(3) of a standard gold sol to just prevent its coagulation by the addition of 1 cm^(3) of 10% NaCl solution to it. Hence, the gold number of gelatin is

10^(-4) g of gelatin is required to be added to 100 cm^(3) of a standa

1.	10^(-4) g of gelatin is required to be added to 100 cm^(3) of a standard gold sol to just prevent its coagulation by the addition of 1 cm^(3) of 10% NaCl solution to it. Hence, the gold number of gelatin is
Answer» 10 1 0.1 0.01 Solution :By definition, gold number is the number of milligrams of dry PROTECTIVE colloids required to just prevent the coagulation of 10mL of red gold sol when 1 ML (or 1 `cm^(3)` ) of 10% NaCl solution is added to it. Here the amount of GELATIN required to protect 10 mL (or 10 `cm^(3)`) of gold sol `=(10^(-4)xx10)/(100)=10^(-5) g` `=10^(-5)xx10^(-3) mg=10^(-2)` mg =0.01 mg `therefore` Gold number =0.01