Saved Bookmarks
| 1. |
The coagulation of 100 mL of a colloidal solution of gold is completely prevented by adding 0.25 g of starch to it before adding 10 mL of 10% NaCl solution. Find out the gold number of starch. |
|
Answer» SOLUTION :10 mL of 10% NaCl solution is added to 100 mL of solution of gold. Thus, 1 mL of 10% NaCl solution has been added to 10 mL solution of gold. SINCE, 100 mL gold solution required = 0.25 g starch `=0.25xx10^(3)` mg starch So, 10 mL gold solution required `=(0.25 xx 10^(3))/(100)xx10` `=25 mg` starch Thus, by definition, the gold NUMBER of starch is 25. |
|