Question

Assign oxidation states to each atom in each of the following species.

1. N₂

_{2. Fe³⁺}

_^3. CuCl₂

4. CH₄

5. Cr₂O_7^2-

_^6. HCO_3^-

Answer 1

1) oxidation state of N2 is zero. (oxidation state in neutral state is zero.)

2) oxidation state of Fe³⁺ is +3

3) oxidation state of Cu in CuCl2 is +2 and Cl is -1

4) oxidation state of C in CH4 is -4 and H is +1

5) oxidation state of Cr in Cr₂O₇^2- is:

2(x) + 7(-2) = -2

2X - 14 = -2

2X = -2 + 14 = +12

X = 12/2 = +6

Therefore, oxidation state of Cr in Cr₂O₇^2- is +6 and oxidation state of O is -2

6) oxidation state of C in HCO₃^- : +1 + X + 3(-2) = -1

1 + X -6 = -1

X = -1 +6 -1 = +4

Therefore, oxidation state of C in HCO3- is +4 and oxidation state of H is +1 and oxidation state of O is -2.