d and f BLOCK ELEMENTS

What is the color change observed at the endpoint of a titration using KMnO₄ as the titrant with a colorless analyte like Fe²⁺?

• Colorless solution turns faint pink/purple
• Pink/purple solution becomes colorless
• Yellow solution turns green
• Blue solution becomes colorless

What is the coefficient of H₂O in the balanced equation 10I⁻ + 2MnO₄⁻ + 16H⁺ → ? Mn²⁺ + ? H₂O + 5I₂?

• 8
• 4
• 16
• 2

What is the main reason for the decomposition of KMnO₄ upon heating?

• Thermal energy provides activation energy
• Light energy
• Electrical energy
• Chemical energy from impurities

What is the oxidation state change of manganese when preparing permanganate from a Mn²⁺ salt?

• +2 to +7
• +7 to +2
• +6 to +7
• +4 to +6

What is the main product formed when potassium permanganate oxidizes iodide ions in acidic solution?

• Iodine
• Iodide
• Potassium iodide
• Periodic acid