Answer:
Step-by-step explanation:
These kinds of equations are very mechanical. They are all done the same way.
First the hydrogen. There are 4 hydrogens on the left and only 2 on the right. So you must put a two in front of the the water.
[ ] CH4 + [ ] O2 → [ ] CO2 + [ 2] H2O
Now the carbons. There's one on the left and one on the right, so they are balanced. I'd put a 1 on both anyway.
[ 1] CH4 + [ ] O2 → [1 ] CO2 + [ 2] H2O
Finally the oxygens. There's 2 on the CO2 and 2 on the water (that 2 in front multiplies the 1 water into 2 oxygens because the right is really H2O + H2O.)
So 2 from CO2 and 2 From H20 makes 4 altogether.
There's only 2 on the right, so you have to multiply the O2 by 2
[1 ] CH4 + [2 ] O2 → [1 ] CO2 + [2 ] H2O