the protective power of the lyophilic colloids es expressed in terms of gold number, a term introduced by Zsigmondy. Gold number is the number of milli - gram of the protective colloid which prevent the coagulation of 10 mLof red gold sol , when 1 mL of a 10 per cent solution of sodium chloride is added to it . thus smaller the gold number of lyophillic colloid, the greater is the protective power. On addition of one mL of sloution of 10 % NaCl to 10 mL. of red gold sol in presence of 0l.025 g of starch the coagultion is just prevented . the gold number of starch is
On addiction of 1ml solution of 10% NaCl to 10ml gold sol in the presence of 0.0250gm mof starch, the coagulation is just prevented Starch has the following gold number
What is protective colloid ?
Following passage describes charcterstics of colloids. Answer the questions at the end of it. Lyophilic colloidal sols are much more stable than lyophobic colloidal sols. This is due to the extensive solvation of lyophilic colloidal sols, which forms a protective layer outside it and thus prevents it from forming associated colloids. Lyophillic colloidal sols also protect lyophobic colloidal sols from precipition by the action of electrolytes. This is due to formation of a protective layer by lyophilic sols outside lyophobic sols. Lyophilic colloidal sols are called protective sols. Gelatin (lyophilic) protects gold sol (lyophobic) from coagulaion on the addition of sodium chloride solution. Protective powers of different colloidal sols are measured in terms of 'gold number' (Zigmody). It is defined as the amount of protective sol in milligrams that prevents the coagulation of 10 mL of a given gold sol on adding 1 mL of 10 percent sodium chloride. Thus smaller the gold number of a lyophillic sol, the greater is the protective power. 0.025g of starch sol is required to prevent coagulation of 10ml gold sol when ImL of 10% Nacl solution is present. What is gold number of starch sol
Gold number of a lyophilic solution is such property that
Define Gold Number.
What is Gold number ?
If the gold number of potato starch is 25, how many grams of it is required to prevent coagulating of 100mL of gold sol on adding 10mL of 10% NaCl solution?
NARENDRA AWASTHI-SURFACE CHEMISTRY-Level 3 - Assertion - Reason Type Questions
