Q.Write balanced equations for

With ample oxygen, methane burns completely to give carbon dioxide and water: $\text{CH}_4 + 2\text{O}_2 \rightarrow \text{CO}_2 + 2\text{H}_2\text{O}$. When the oxygen supply is restricted -- for example, a stove or heater burning in a poorly ventilated, enclosed room -- combustion is incomplete and produces carbon monoxide instead: $2\text{CH}_4 + 3\text{O}_2 \rightarrow 2\text{CO} + 4\text{H}_2\text{O}$. Between the two products, carbon monoxide is by far the more immediately dangerous to a person breathing it in an enclosed space. $\text{CO}_2$ at typical indoor concentrations is not directly toxic; it becomes hazardous mainly at very high concentrations by displacing breathable air. CO, on the other hand, is acutely toxic even at low concentrations because it binds to haemoglobin roughly 200 times more strongly than oxygen, activ …

Balance the two combustion equations separately (complete uses more $\text{O}_2$ per mole of fuel than incomplete), then compare the two products by their …

Assuming $\text{CO}_2$ is the more dangerous product simply because it is more talked about as a pollutant -- in an enclosed …