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

Concept:
Lugol's solution is an aqueous iodine solution. It contains iodine and potassium iodide.

Step 1: Composition of Lugol's solution.
Lugol's solution is commonly prepared using iodine and potassium iodide in water.

Step 2: Role of potassium iodide.
Iodine has low solubility in water. Potassium iodide helps iodine dissolve by forming polyiodide ions. \[ I_2 + I^- \rightarrow I_3^- \]

Step 3: Standard concentration.
Lugol's solution contains: \[ 5% \text{ iodine} \] and \[ 10% \text{ potassium iodide} \]

Step 4: Checking the options.
Option (D) gives the correct composition as \(5%\) iodine and \(10%\) potassium iodide.

Step 5: Final answer.
Therefore, Lugol's solution contains \(5%\) iodine and \(10%\) potassium iodide. \[ \boxed{5;10} \]