Question

What are the oxidation numbers of each element in the following: Na^2S^2O^3 ?

Answer 1

`Na:+1`

`S:+2`

`O:-2`

Explanation:

We got:

`Na_2S_2O_3`

We will assume normal oxidation numbers for oxygen and sodium.

Oxygen has an oxidation number of `-2`. Here there are three oxygens, so the total charge is `-2*3=-6`.

Sodium has an oxidation number of `+1`. So, the total charge of them will be `+1*2=+2`, since there are two sodiums.

If the molecule is neutral, then the total charge is `0`.

Let `x` be the charge of `S_2`.

We got:

`x+2-6=0`

`x-4=0`

`x=4`

So, two sulfurs have a charge of `+4`. Since they are the same atom, they both are likely to have the same charge, and so we divide the number by `2` to get:

`4/2=2`

Each sulfur atom has a charge of `+2`.