What is the oxidation state of C in NaHCO3

A. +1
B. -6
C. -2
D. +4

Total charge of this neutral molecule = 0
Sodium, Na and Hydrogen, H are in Group 1; hence both charge = +1
Oxide, O with proton number of 8 (in group 16); hence charge = -2
Assume carbon charge = X

Total Charge NaHCO3 = 0
(+1) + (+1) + X + (3 x -2) = 0
+2 – 6 + X = 0
-4 + X = 0
X = +4

Therefore, the charge of Carbon = +4

Cheers^_^

+4

It is a neutral compound, so the total is zero. Assign the H +1 and the oxygens -2. (H is +1 in any compound except a metal hydride, oxygen is -2 in any compound except a peroxide or when bonded to fluorine.) The Na is +1, this is an ionic compound and it is the sodium ion. Therefore

+1 for Na +1 for H -2(3) for the oxygens + x for the carbon totals zero
1 + 1 -6 + x = 0 and x =4, the oxidation number for the carbon

The way to do this type of problem is to simply total up the charges; for a neutral molecule the total charge = zero, for an ion it is the charge on the ion.

Na = +1
H = + 1
O = -2
1 + 1 + C -3[2] = 0 where C is charge on Carbon
C = +4
Answer is D