Question

What needs to happen for the equation CH4 + O2 → CO2 + H2O to be balanced?

Answer 1

CH4 + 2O2 -> CO2 + 2H2O

One carbon on both sides

4 Oxygen on both sides

4 Hydrogen on both sides

Answer 2

C is balanced on both sides
H is 4 on left side
2 on left side

To balance H
CH4+O2=>CO2+2H2O
H is balanced

In our new equation
O is 2 on left side
4 on right side
So
CH4+2O2=>CO2+2H2O

Now the equation is balanced
hope this helps you