Question

When methane undergoes combustion in air, the oxidation number of C ____________.

Options

• increases from −4 to +4

• decreases from +4 to −4

• increases from −4 to 0

• decreases from +4 to +2

Answer 1

When methane undergoes combustion in air, the oxidation number of C increases from −4 to +4.

Explanation:

\[\begin{array}{cc}
\ce{\underset{-4}{\underset{^}{C}}H_{4(g)} + O_{2(g)} ->\underset{+4}{\underset{^}{C}}O_{2(g)} + 2H2O_{(l)}}\end{array}\]