What is oxidation number of oxygen atom in O2F2 and OF2 respectively a +1 and +2 b +2 and +1 C +2 and +2 D +1 and +1?

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I mean oxygen is electronegative element it should have negative oxidation number Also how it is able to make bond with fluorine which itself is electronegative? Why the oxidation number of oxygen is +2.?

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The correct answer is +1.

Key Points

The oxidation number is the total number of electrons that an atom either gains or loses in order to form a chemical bond with another atom.
It is also called an oxidation state.

Important Points

The oxidation number of oxygen in most compounds is -2.
However, there are some exceptions.
- In peroxides (e.g., H2O2, Na2O2), each oxygen atom is assigned an oxidation number of –1.
- In superoxides (e.g., KO2, RbO2) each oxygen atom is assigned an oxidation number of –(½).
- Oxygen difluoride (OF2) has an oxidation number of +2.
- Dioxygen difluoride (O2F2), has an oxidation number of +1.
The number assigned to oxygen will depend upon the bonding state of oxygen but this number would now be a positive figure only.

Additional Information

In elements, in the free or the uncombined state, each atom bears an oxidation number of zero. Evidently, each atom in H2, O2, Cl2, Na, Mg, Al has the oxidation number zero.
For ions composed of only one atom, the oxidation number is equal to the charge on the ion. Thus Na+ ion has an oxidation number of +1; Mg2+ ion, +2; Fe3+ ion, +3; and so on.
In their compounds, all alkali metals have an oxidation number of +1, and all alkaline earth metals have an oxidation number of +2. Aluminum is regarded to have an oxidation number of +3 in all its compounds.
The oxidation number of hydrogen is +1, except when it is bonded to metals in binary compounds (compounds containing two elements). For example, in LiH, NaH, and CaH2, its oxidation number is -1.
In all its compounds, fluorine has an oxidation number of -1. Other halogens (Cl, Br, and I) also have an oxidation number of -1, when they occur as halide ions in their compounds. Chlorine, bromine, and iodine when combined with oxygen, for example in oxoacids and oxoanions, have positive oxidation numbers.

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Answer

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Hint: Oxidation state represents the degree of oxidation (loss of electrons) of an atom in a chemical compound and Fluorine is the most electronegative element on the periodic table, which means that it is a very strong oxidizing agent and accepts other elements electrons.

Complete answer:

Now we determine the most electronegative atom.Oxygen is the second most electronegative element. It has an electronegativity of 3.5 on the Pauling scale. That means if oxygen combines with an element which is more electronegative than it will surely possess a positive oxidation state.Fluorine being the first most electronegative element than oxygen (electronegativity of 4.0 on Pauling scale) will in any case (except in fluorine gas), oxidation state of fluorine is - 1 in all its compounds. So, the oxidation state of oxygen will be positive. Being in the group 17 fluoride ion would gain an electron to a -1 charge, so each has an oxidation number of -1.Let us calculate the oxidation state of oxygen-Let be ‘x’ is an oxidation number of oxygen.Oxidation number of \[{F_2}\] is \[ - 1\].Net charge is zero because the compound is neutral.2x - 2 = 0 x = $\dfrac{2}{2}$x = 1So the oxidation number of oxygen in \[{O_2}{F_2}\] is + 1.

The oxygen has an oxidation number of + 1 each.

Note: Fluorine in its gaseous form ($F_2$) has zero oxidation state. The oxidation number of other halogens (Cl, Br, I ) is also -1, except when they are combined with oxygen. Oxygen in most of its compounds exist in -2 oxidation state.