Question 12 of 31intermediate🔧 ApplyShort Answer2 marks

Fluorine reacts with ice and results in the change: H₂O(s) + F₂(g) → HF(g) + HOF(g) Justify that this reaction is a redox reaction.

Correct Answer

To justify that the given reaction is a redox reaction, we assign the oxidation numbers to the elements involved. In the reactants, the oxidation number of fluorine in F2(g)F_2(g) is 00, and the oxidation number of oxygen in H2O(s)H_2O(s) is −2-2.

In the products, fluorine is the most electronegative element and cannot exhibit a positive oxidation state, so its oxidation number in both HF(g)HF(g) and HOF(g)HOF(g) is −1-1. In HOF(g)HOF(g), hydrogen is +1+1 and fluorine is −1-1, making the oxidation number of oxygen 00.

Here, the oxidation number of fluorine decreases from 00 to −1-1, indicating reduction. Simultaneously, the oxidation number of oxygen increases from −2-2 to 00, indicating oxidation. Since both oxidation and reduction occur simultaneously, the reaction is a redox reaction.

Exercise: EXERCISES | Q: 7.4 | (Page Page 18)
For More Understanding

Explanation

The reaction involves a change in oxidation states. Fluorine, being the most electronegative element, goes from 0 in F2 to -1 in HF and HOF (reduction). Oxygen goes from -2 in H2O to 0 in HOF (oxidation). Because oxidation and reduction happen together, it is a redox reaction.

Solution Steps

  1. Step 1: Assign oxidation numbers in reactants: F in F2F_2 is 00, O in H2OH_2O is −2-2.

  2. Step 2: Assign oxidation numbers in products: F in HFHF and HOFHOF is −1-1 (as it is the most electronegative). In HOFHOF, H is +1+1 and F is −1-1, so O is 00.

  3. Step 3: Identify changes: F is reduced (00 to −1-1) and O is oxidized (−2-2 to 00).

  4. Step 4: Conclude that since both oxidation and reduction occur simultaneously, it is a redox reaction.

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