Question

Oxidation number of S in ${{H}_{2}}S{{O}_{5}}$ is 6. This is observed because:
A. there are five oxygen atom in molecule
B. the hydrogen atom is directly linked with non-metal
C. there is peroxide linkage in the molecule
D. the sulphur atom shows coordinate linkage

Answer 1

Hint In order to solve this question, we have to find the oxidation state by the normal state, because by doing so we can observe whether there is an anomaly or not. If there is some anomaly then we will mention the structure of the compound, and can see what is different and will get the answer.

Complete answer:
We should follow some basic rules in this case. It is seen that hydrogen can have charge depending on other atoms. Non-metals are found to have negative charge and metals have positive charge.
As per the rules the oxidation number would be:
$\begin{align}
& {{H}_{2}}S{{O}_{5}} \\
& 2H+S+5O=0 \\
& 2+S-10=0 \\
& S=8 \\
\end{align}$
- But in reality it is found that the oxidation number of S in ${{H}_{2}}S{{O}_{5}}$ is 6. We should see here that all this happens because of the structure of the compound. As it is found that oxygen has the peroxy-linkage that reduces the pseudo charge over the atom. We can see the structure of ${{H}_{2}}S{{O}_{5}}$.

Hence, we can conclude that the correct option is (c), that is Oxidation number of S in ${{H}_{2}}S{{O}_{5}}$ is 6. This is observed because there is peroxide linkage in the molecule.

Note: As we know that oxidation number is the pseudo charge on the atom. It is found that elements can have different oxidation numbers for the same type of atom in the same compound, just like here in this case of oxygen. This is mainly due to the variety in bonds.