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In which of the following changes there is a transfer of two electrons?

Correct answer: A. MnO2-4→ MnO2

  • A. MnO2-4→ MnO2
  • B. MnO-4→ Mn+2
  • C. CrO2-4→ Cr+3
  • D. Cr2O2-7 → 2Cr+3

Explanation

A. MnO2-4→ MnO2 oxidation number of Mn in MnO4-2 is +6 and in MnO2 is +4. Hence there is transfer of two electrons.B. MnO-4→ Mn+2Oxidation number of Mn in MnO4- is +7 and in Mn2+ is +2. Hence there is transfer of 5 electrons. C. CrO2-4→ Cr+3Oxidation number of Cr in CrO42- is +6 and in Cr+3 is +3. Hence there is transfer of 3 electrons. D. Cr2O2-7 → 2Cr+3Oxidation number of chromium in Cr2O72- is +6 and in Cr3+ is +3. Hence there is transfer of 3 electrons.

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