Question

Oxidation number of xenon in $XeO{F_2}$ is $\_\_\_\_\_\_\_\_\_\_$.
A: Zero
B: $2$
C: $4$
D: $3$

Answer 1

Hint: Oxidation number of an atom is the charge that an atom will possess if the compound was ionic. Ionic compounds are compounds made up of ions. These ions are basically atoms or molecules that gain or lose electrons, giving them a net positive or negative charge.

Complete step by step answer:
$XeO{F_2}$ is a compound of xenon with oxygen and fluorine. Xenon is a noble gas. This means the octet of xenon is full. It will not react with any atom as it has stable electronic configuration. But oxygen and fluorine are highly electronegative elements and hence are capable of making bonds with xenon. That is why all the compounds of xenon exist with oxygen and fluorine only. In this question we have to find the oxidation state of xenon in $XeO{F_2}$. This is the exceptional case in case of oxidation number of oxygen. Fluorine being the most electronegative element will possess negative charge due to which there will be positive charge on oxygen. This is possible only when oxygen makes a compound with fluorine. Fluorine requires only one electron to complete its octet. This means the oxidation number of fluorine is $ - 1$. Oxygen needs two electrons to complete its octet. This means the oxidation number of oxygen should be $ - 2$ but because of the presence of fluorine its oxidation number is $ + 2$. Let the oxidation number of xenon be $x$. No net charge on the molecule is given. This means the compound as a whole is neutral and the sum of oxidation numbers of all the atoms is zero.
Oxidation number of xenon is $x$
Oxidation number of fluorine is $ - 1 \times 2 = - 2$ (since there are two fluorine atoms)
Oxidation number of oxygen is $ + 2$
As a whole compound is neutral therefore,
$x + 2 - 2 = 0$
Solving this we get $x = 0$
This means the oxidation number of xenon is zero.
So, the correct answer is option A that is zero.

Note:
Oxidation number is also called an oxidation state which is the total number of electrons that an atom either gains or loses to form bonds with another atom. If the oxidation state is positive that means the atom acquires electrons in a chemical reaction and the negative oxidation state means the atom donates electrons in a chemical reaction.