What is oxidation number? Mention the working rules used to calculate the oxidation number of an atom in a given species. Calculate the oxidation number of S in `Na_(2)S,Na_(2)SO_(3),Na_(2)SO_(4),Na_(2)S_(2)O_(3) and Na_(2)S_(4)O_(6)`.

Explanation

The oxidation number of S in `Na_(2)S_(4)O_(6)` Oxidation number of `Na = +1, O= -2, S= x`, then substituting oxidation number values in neutral molecule `Na_(2)S_(4)O_(6)`
We get, `(+1) xx 2 + (x) xx 4 + (-2) xx 6= 0`
`2 + 4x-12=0`
`4x= +12-2= +10`
`x= + (10)/(4) = +(5)/(2)`
`therefore` The oxidation number of S in `Na_(2)S_(4)O_(6)` is +2.5.