Question

What is the change in oxidation number of carbon in the following reaction?
$CH_4(g) + 4Cl_2 (g) \rightarrow CCl_4(l) + 4HCl (g)$

• A. +4 to +4
• B. 0 to +4
• C. -4 to +4
• D. 0 to -4

Answer 1

Answer: (C)

-4 to +4

Answer 2

The correct option is(C): -4 to +4.

Oxidation number of $C$ in $CH_4$ is $- 4$
as x + 4 = 0$$\,\, x = - 4 (x is oxidation state of carbon)
oxidation of $C$ in $CCl_4$ is $+ 4$
as $x - 4 = 0 \,\,\,x = + 4$
$\therefore$ Change in oxidation state of carbon is from $-4$ to $+4$