Question

# $CH_{ 4 } + 2O_{ 2 } \rightarrow CO_{ 2 } + H_{ 2 }O$ is:A. Combustion reactionB. Redox reactionC. Both A and BD. None of the above

Hint: You just need to recall the definitions of combustion and redox reactions. Combustion is the process of burning something and redox reaction is a type of chemical reaction that involves a transfer of electrons between two species. You will finally get the correct answer to this question.

$CH_{ 4 } + 2O_{ 2 } \rightarrow CO_{ 2 } + 2H_{ 2 }O$
It is a redox reaction because the oxidation number of oxygen in the $O_{ 2 }$ molecule is 0. But in water, its oxidation number is −2, so it is a reduction. In methane, the oxidation number of H = −1 and in $H_{ 2 }O$ its oxidation number of H is +1, so it is oxidation.
Combustion reaction - A combustion reaction is a reaction in which a substance reacts with oxygen gas, releasing energy in the form of light and heat. Combustion reactions must involve $O_{ 2 }$ as one reactant.
$CH_{ 4 } + 2O_{ 2 } \rightarrow CO_{ 2 } + 2H_{ 2 }O$