Question

\( KMnO_4 \) is a:

• A. Primary standard
• B. Secondary standard
• C. Neither
• D. Reducing agent in acidic medium

Hint:

Potassium Permanganate ($KMnO_{4}$) is a powerful oxidizer but a "Secondary" standard because it decomposes easily.

Answer 1

The Correct Option is B

Step 1: Concept
Standards in analytical chemistry are substances with a known purity used to determine the concentration of other solutions.

Step 2: Meaning
A primary standard is highly pure and stable, while a secondary standard is a substance whose concentration is determined by titration against a primary standard because it is not available in a completely pure or stable form.

Step 3: Analysis
Potassium permanganate ($KMnO_{4}$) is difficult to obtain in a perfectly pure state and can be decomposed by light and organic matter. Therefore, its solution must be standardized against a primary standard like oxalic acid.

Step 4: Conclusion
Because of its instability and the requirement for standardization, $KMnO_{4}$ is classified as a secondary standard. Final Answer: (B)