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MDCAT
Chemistry
2024

Chemistry · Electrochemistry

Work through this past-paper style MCQ, then read the full explanation. Practice more chemistry questions on mMCQ with adaptive drills and topic analytics.

Question

What change in oxidation number of Cu takes place in the following reaction: Cu+4HNO3​→Cu(NO3​)2​+2NO2​+2H2​O

Options
  • A

    0 to -1

  • B

    0 to +1

  • C

    0 to -2

  • D

    0 to +2

Explanation

Elemental copper (Cu) has an oxidation number of 0. In Cu(NO3)2, copper has an oxidation number of +2.

Copper's oxidation number increases, not decreases, in this reaction.

While copper does gain a positive oxidation state, it gains +2, not +1

Copper does not gain a negative oxidation state in this reaction.

Elemental copper (Cu) has an oxidation number of 0. In Cu(NO3)2, copper has an oxidation number of +2.

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Tagged under Chemistry · Electrochemistry · 2024