Colloids

To coagulate a positive sol, negatively charged ions (anions) are used. According to the Hardy-Schulze rule, the coagulating power of an ion is proportional to the magnitude of its charge. The charges are: ( ), ( ), and ( ). Thus, the order of coagulating power is: In terms of the labels: I III II. This matches option 4. Thus, the correct answer is I III II.

Definition:
The gold number of a protective colloid is defined as the minimum amount of the colloid (in milligrams) required to prevent the coagulation of 10 mL of a gold sol when 1 mL of 10% sodium chloride (NaCl) solution is added.

Steps to determine the gold number of 'X':

1. Understand the data provided:
   The image linked in the problem (presumably) provides data showing different concentrations of colloid ‘X’ and observations on whether coagulation occurred.
2. Identify the effective concentration:
   From the table, find the smallest concentration of 'X' that prevents coagulation when 1 mL of 10% NaCl is added.
   This concentration is typically given in mg/mL.
3. Calculate the gold number:
   Multiply the effective concentration (in mg/mL) by the total volume of the colloid solution (10 mL).
   For example, if the effective concentration is 2.5 mg/mL:
   
   Gold number = 2.5 mg/mL × 10 mL = 25 mg

Conclusion:
Therefore, the gold number of ‘X’ is 25, which corresponds to the correct answer choice provided.

The question asks about which sol is used as an intramuscular injection. Intramuscular injections require a sol that is safe for such an application and has properties allowing it to be effectively absorbed into the muscle tissue.

The options given are:

• Antimony Sol
• Silver Sol
• Emulsion of Milk of Magnesia
• Gold Sol

Among these, Gold Sol is used as an intramuscular injection. Gold Sol is known for its medical applications, particularly in the treatment of rheumatoid arthritis. It is prepared as a colloidal solution and is used for its anti-inflammatory properties. The finely dispersed particles in Gold Sol aid in ensuring compatibility with biological systems, making it a suitable choice for intramuscular administration.