Question

How would you calculate oxidation number?

Answer 1

1.the oxidation state of free element is always zero.

2.The O.S of monoatomic ion =charge of ion.

3.The O. S of H is + 1 but it is -1 ,if combined with less electrnegative element.

4. The O. S of O is usually -2 but it is -1 in peroxides.

5.TheO.S of group 1 ekements is +1 and that of group 2 elements is +2.

6.The O. S of group 17 elements in bibary compounds is -1.

7.The sum of the oxidation number of all the atoms i a neutral compound is 0.

8.The sum of the oxidation numbers in a polyatomic ion is equal to charge of an ion.

ex:NaSO4- to find out O.S of sulphur

firstly, let the value of x

The O. S of Na is +1 and that of O is -2.

So, it is as follows

+1 +x+4(-2)=0

+1+x-8=0

×+(-7)=0

x= +7