Question

Lugol's solution contains ________% iodine and _________% potassium iodide.

• A. 1; 2
• B. 2; 1
• C. 10; 5
• D. 5; 10

Hint:

Lugol's solution contains 5% iodine and 10% potassium iodide.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Lugol's solution, also known as Strong Iodine Solution, is used as an antiseptic, disinfectant, and for treating certain thyroid conditions.
Step 2: Detailed Explanation:
1. Composition: It is an aqueous solution of iodine and potassium iodide.
2. Specific Concentrations: The standard IP/BP formulation for Lugol's solution requires 5% w/v Iodine and 10% w/v Potassium Iodide in purified water.
3. Role of KI: Iodine is poorly soluble in water. Potassium iodide is added to react with iodine to form the highly soluble tri-iodide complex (\(I_3^-\)), which keeps the iodine in solution.
Step 3: Final Answer:
The correct percentage of ingredients in Lugol's solution is 5% Iodine and 10% Potassium Iodide.