What is the oxidation state of C in NaHCO3?
O A. +4
O B. -6
O C. +1
OD. -2

Explanation:

The HCO₃ in NaHCO₃ has an oxidation state of -1. We know this because of the charge on HCO₃ and also by the fact that Na is a group 1 metal that always has a +1 oxidation state.

The sum of the oxidation states of the components of HCO₃ has to be equal to -1

⇒  H + C + 3 O  =  - 1

     A rule of redox is that Oxygen always has a - 2 oxidation state and H usually has a + 1 oxidation state

⇒ 1  + C + 3(-2)  = - 1     [make C the subject of the equation and simplify]

⇒                   C = -1 - 1 + 6

                      C = + 4

b.final