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A chemist attempts to reduce an acidified solution of . Passing ordinary gas through the solution yiHydrogen Chemistry Question

Question

A chemist attempts to reduce an acidified solution of $KMnO_4$. Passing ordinary $H_2$ gas through the solution yields no color change. However, adding Zinc granules directly to the acidified $KMnO_4$ solution rapidly decolourises it. Which specific form of hydrogen is responsible for this enhanced reducing action?

Answer: C

💡 Solution & Explanation

Ordinary molecular $H_2$ is relatively inert due to its high bond enthalpy. When Zn reacts with acid, it produces Nascent Hydrogen ($[H]$) *in situ*, which has excess energy from its formation and acts as a vastly superior reducing agent, instantly decolourising $KMnO_4$.

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