Redox Titration
Easychemistry
KMnO4 acts as self-indicator because:
Select the correct option:
Solution
Incorrect! Answer:
Purple permanganate decolorizes upon reduction to Mn2+
- Color Profile: Potassium Permanganate (KMnO4) is a deep purple solution due to the MnO4− ion.
- Titration Event: In a redox titration (acidic medium), MnO4− is reduced to the Mn2+ ion, which is virtually colorless (very faint pink).
- Endpoint Detection: During titration, the added purple drop is immediately decolorized as it reacts with the reducing agent.
- Mechanism: Once the reducing agent is exhausted, the very next drop of KMnO4 is not consumed. Its own purple color remains in the flask.
- Observation: A permanent, persistent faint pink color marks the endpoint without needing an external indicator.
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About This Question
- Subject
- chemistry
- Chapter
- practical chemistry
- Topic
- redox titration
- Difficulty
- Easy
- Year
- 2025
Solution
Correct Answer:
Purple permanganate decolorizes upon reduction to Mn2+
- Color Profile: Potassium Permanganate (KMnO4) is a deep purple solution due to the MnO4− ion.
- Titration Event: In a redox titration (acidic medium), MnO4− is reduced to the Mn2+ ion, which is virtually colorless (very faint pink).
- Endpoint Detection: During titration, the added purple drop is immediately decolorized as it reacts with the reducing agent.
- Mechanism: Once the reducing agent is exhausted, the very next drop of KMnO4 is not consumed. Its own purple color remains in the flask.
- Observation: A permanent, persistent faint pink color marks the endpoint without needing an external indicator.
This easy difficulty chemistry question is from the chapter practical chemistry, covering the topic of redox titration. It appeared in the 2025 exam.
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