Statement (A): Oxidation number of fluorine is −1.
Statement (B): Oxidation number of sodium is +1.
Statement (C): In peroxides, oxygen exhibits +1/ 2 oxidation state.

see full answer

Start JEE / NEET / Foundation preparation at rupees 99/day !!

21% of IItians & 23% of AIIMS delhi doctors are from Sri Chaitanya institute !!

An Intiative by Sri Chaitanya

A and B are correct but C is incorrect

All the above statements are incorrect

All the above statements are correct

A and B are incorrect but C is correct

answer is C.

(Unlock A.I Detailed Solution for FREE)

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Detailed Solution

Fluorine Always Shows -1 Oxidation Number
The oxidation number of fluorine is always -1 in its compounds. This is because fluorine is the most electronegative element in the periodic table. It always pulls electrons towards itself in chemical bonds.
- Example 1: In HF (hydrogen fluoride), fluorine has an oxidation number of -1 because it attracts the shared electron pair from hydrogen.
- Example 2: In OF₂ (oxygen difluoride), fluorine still shows an oxidation number of -1, even though oxygen is less electronegative than fluorine. In this compound, fluorine's dominance keeps its oxidation number fixed at -1.
This unique property makes the oxidation number of fluorine a constant -1 in all its compounds.
Sodium Shows +1 Oxidation Number
Sodium, being an alkali metal, belongs to Group 1 of the periodic table and has the electronic configuration ns¹. It easily loses one electron to form a +1 charge, making its oxidation number +1 in compounds.
- Example 1: In NaH (sodium hydride), sodium has an oxidation number of +1, while hydrogen has an oxidation number of -1.
- Example 2: In Na₂S (sodium sulfide), sodium again shows an oxidation number of +1, while sulfur takes a -2 oxidation state to balance the compound.
Oxygen in Peroxides Shows -1 Oxidation Number
Oxygen usually has an oxidation number of -2, but in peroxides, such as H₂O₂ (hydrogen peroxide) or Na₂O₂ (sodium peroxide), it shows an oxidation number of -1. This is because the peroxide ion (O₂²⁻) consists of two oxygen atoms bonded together, with each oxygen atom contributing to the overall -2 charge of the ion.
- Example 1: In Na₂O₂, the peroxide ion (O₂²⁻) splits the -2 charge equally, giving each oxygen an oxidation number of -1.
- Example 2: In H₂O₂, the same principle applies, where each oxygen atom in the peroxide ion has an oxidation number of -1.