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Q88 (NDA-II/2010) Science & Technology › Basic Science (Physics, Chemistry, Biology) › Basic chemical principles Answer Verified

In the reaction 4Fe + 30, 4Fes+ + 602~ Which of the following statements is incorrect?

Result
Your answer:  ·  Correct: D
Explanation

In the chemical reaction 4Fe + 3O2 → 4Fe3+ + 6O2–, iron (Fe) starts in its elemental state with an oxidation number of 0 and increases to +3 in the product [t4]. This increase in oxidation state signifies that metallic iron loses electrons and is therefore oxidized, not reduced [t2, t5]. Consequently, metallic iron acts as the reducing agent because it donates electrons to oxygen [t2, t7]. Oxygen (O2) starts at an oxidation state of 0 and decreases to -2, meaning it gains electrons and is reduced; thus, it acts as the oxidizing agent [t2, t5]. Since both oxidation and reduction occur simultaneously, it is a redox reaction [c1, t3]. Statement 4 is incorrect because metallic iron is oxidized to Fe3+, whereas the statement claims it is reduced [t1, t7].

Sources

  1. [1] https://en.wikipedia.org/wiki/Reducing_agent
  2. [2] Science , class X (NCERT 2025 ed.) > Chapter 1: Chemical Reactions and Equations > CuO +H Cu+H O 2 2 → Heat (1.29) > p. 12
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