Question

What is the oxidation number of carbon in each of the following substances?

a) CO

b) CO₂

c) C₂H₆

d) C

e) CO₃^2-

f) CH₃OH

Answer 1

a)

Oxidation number of O = -2

lets the oxidation number of C be x

use:

1* oxidation number (O) + 1* oxidation number (C) = net charge

1*(-2)+1* x = 0

-2 + 1 * x = 0

x = 2

So oxidation number of C = +2

Answer: +2

b)

Oxidation number of O = -2

lets the oxidation number of C be x

use:

2* oxidation number (O) + 1* oxidation number (C) = net charge

2*(-2)+1* x = 0

-4 + 1 * x = 0

x = 4

So oxidation number of C = +4

Answer: +4

c)

Oxidation number of H = +1

lets the oxidation number of C be x

use:

6* oxidation number (H) + 2* oxidation number (C) = net charge

6*(+1)+2* x = 0

6 + 2 * x = 0

x = -3

So oxidation number of C = -3

Answer: -3

d)

This is single element

Its oxidation state is 0

Answer: 0

e)

Oxidation number of O = -2

lets the oxidation number of C be x

use:

3* oxidation number (O) + 1* oxidation number (C) = net charge

3*(-2)+1* x = -2

-6 + 1 * x = -2

x = 4

So oxidation number of C = +4

Answer: +4

Only 4 parts at a time