What is the correct chemical equation for the reaction between methane and oxygen to produce carbon dioxide and water?

The answer to your question is:   CH₄     +    3/2 O₂     ⇒     CO₂    +   2 H₂O

Explanation:

Methane = CH₄

Oxygen = O

Carbon dioxide = CO₂

Water = H₂O

                      CH₄     +    3/2 O₂     ⇒     CO₂    +   2 H₂O

        This is the balanced equation

when [oh-] is 10-5  m, and [h3o+] is 10-9  m, the poh is 5 and ph is 9. again in both cases the sum of ph and poh is 14. however, the hydrogen ion concentration is not always going to be equal to exactly 1 x 10 raised to a negative number. for example, we skipped over the value of 2.0 x 10-7.