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Q9 (NDA-I/2014) Science & Technology › Basic Science (Physics, Chemistry, Biology) › Basic chemical principles Answer Verified

Which of the following is correct regarding the reaction of fluorine with water? 2F2(g) + 2H2O(l) ----> 4H+ (aq) + 4F- (aq) + O2(g)

Result
Your answer:  ·  Correct: B
Explanation

In the reaction 2F2(g) + 2H2O(l) → 4H+(aq) + 4F-(aq) + O2(g), fluorine (F2) acts as a powerful oxidizing agent. In its elemental state, fluorine has an oxidation state of 0, which decreases to -1 in the fluoride ion (F-), meaning fluorine is reduced. Conversely, oxygen in water (H2O) has an oxidation state of -2. During the reaction, it is converted into molecular oxygen (O2), where its oxidation state increases to 0. According to the principles of redox reactions, an increase in oxidation state signifies oxidation. Therefore, water is oxidized to O2 because the oxygen atoms lose electrons to the fluorine atoms. Option 1 is incorrect as fluorine is reduced, not oxidized. Option 3 is incorrect because hydrogen's oxidation state remains +1 throughout the reaction. Option 4 is incorrect as fluorine's state changes from 0 to -1.

Sources

  1. [1] Science , class X (NCERT 2025 ed.) > Chapter 1: Chemical Reactions and Equations > CuO +H Cu+H O 2 2 → Heat (1.29) > p. 12
  2. [2] https://www.khanacademy.org/science/ap-chemistry-beta/x2eef969c74e0d802:chemical-reactions/x2eef969c74e0d802:oxidation-reduction-redox-reactions/a/oxidation-number
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