Following passage describes charcterstic...

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

0.025

`2.5 xx 10^(-5)`

`0.25`

`25`

Verified by Experts

The correct Answer is:

Gold sol is expressed in m.gr - 0.025 gr = 25 m.gr

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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. Gold number of haemoglobin is 0.03. Hence, 10 mL of gold sol will require haemoglobin so that gold is not coagulated by ImL of 10% NaCl solution

0.03 mg

30 mg

0.30 mg

3 mg

`1, 1, 1`

`1, 2, 3`

`1, 1/2, 1/3`

`6, 3, 2`

The colloidal particles have positive charge

The colloidal particles have negative charge

The colloidal particles are solvated

There are strong electrostatic repulsions between the negatively charged colloidal particles