Question

Question #30c09

Answer 1

The hydrogen carbonate ion is `HCO_3^(_)`. Since there a 4 of them the lead ion must be `Pb^(4+)` hence its oxidation state must be +4.

Oxygen is always assigned -2 in compounds (except with fluorine).

So in the hydrogen carbonate ion oxygen contributes 3 x -2 = -6.

So carbon is +4 and H is +1.

This is because the charge on the ion is the arithmetic sum of all the oxidation states:

+4 +1 -6 = -1.