What is the oxidation number of carbon in NaHCO3?

To find the oxidation number of carbon in NaHCO3, we need to know the oxidation numbers of the other elements first.

1. Sodium (Na) is in group 1 of the periodic table and has an oxidation number of +1.

2. Hydrogen (H) usually has an oxidation number of +1.

3. Oxygen (O) usually has an oxidation number of -2.

4. There are three oxygen atoms, so the total oxidation number for oxygen is 3*(-2) = -6.

5. The total oxidation number of a neutral compound is zero. So, the sum of the oxidation numbers of all the atoms in NaHCO3 should be zero.

6. Let's denote the oxidation number of carbon as x. So, we have:

   +1 (for Na) +1 (for H) + x (for C) -6 (for O) = 0

7. Solving for x gives: x = +4.

So, the oxidation number of carbon in NaHCO3 is +4.