JEE Main2012ChemistrySurface ChemistryActual
On addition of 1 ~mL of 10 % NaCl solution to 10 mL gold sol in the presence of 0.025 ~g of starch, the coagulation is just prevented. Starch has gold number
Options
- A2.5
- B25
- C0.25
- D0.025
Correct answer
B. 25
Step-by-step solution
Gold Number is the minimum amount of lyophilic colloide in miligrams (starch in given case) which prevents the flocculation of 10 ml gold sol by the addition of 1 ml of 10 % NaCl solution. Gold number = miligram of starch =0.025 10^3 mg =25