Question

When methane is treated with oxygen gas at room temperature, it does not react with oxygen. However, when a match stick is lit in the presence of methane gas, the gas starts burning to releasing carbon dioxide and water, as well as heat energy.

The above reaction does not occur at room temperature because

Answer 1

Because combustion is kinetically hindered even though it is thermodynamically favorable. Methane + O2 to CO2 + H2O releases a lot of energy overall, but to get the reaction started you must break strong C–H (and O=O) bonds and form reactive radical species. At room temperature molecules do not have enough energy to overcome that large activation energy (and direct reaction with ground‑state triplet O2 is spin‑forbidden), so no reaction occurs. A lit match supplies the required heat and radicals to initiate the chain reaction; once started the exothermic process sustains itself.