Answer:
14 moles of O2.
Step-by-step explanation:
You can see that in the chemical reaction, 2 moles of O2 reacted, produces 2 moles of H2O. You can realize that the molar ratio between these two compounds is 1:1, this means that if we react 2 moles of oxygen with CH4, we will produce 2 moles of H2O, or if we want to react 5 moles of oxygen with CH4, we will produce 5 moles of H2O. You can see this better, like this:
![\begin{gathered} 2\text{ moles O}_2\rightarrow2\text{ moles H}_2O \\ ?\text{ moles O}_2\rightarrow14\text{ moles H}_2O. \end{gathered}](https://img.qammunity.org/2023/formulas/chemistry/college/5io6jz3d1g6j0wckcpklbdy1t5rbk0kk37.png)
The calculation of this rule of three can be visualized:
![14\text{ moles H}_2O\cdot\frac{2\text{ moles O}_2}{2\text{ moles H}_2O}=14\text{ moles O}_2.](https://img.qammunity.org/2023/formulas/chemistry/college/99st65e760gjx324hac3kbhvu7rwpwdi0g.png)
We need 14 moles of O2 to produce 14 moles of H2O.