Answer:
A: CH4 + 2O2 -> CO2 + 2H2O
Explanation:
CH4 + O2 -> CO2 + H2O
Count how many elements they are in all molecules for the reactants and for the products.
For the reactants:
C = 1 element
H = 4 elements
O = 2 elements
For the products:
C = 1 element
O = 2 elements
H = 2 elements
O = 1 element
2 oxygen atoms + 1 oxygen atoms = 3 oxygen atoms total on the products side.
To balance this equation, we need to add 2 more elements of hydrogen and 2 more elements of oxygen. Therefore, we add a 2 to the coefficient of O2 for the reactants side and add a 2 to the coefficient of H2O for the products side.
Now let us try it.
CH4 + 2O2 -> CO2 + 2H2O
Count how many elements they are in all molecules for the reactants and products.
For the reactants:
C = 1 element
H = 4 elements
O = 4 elements
For the products:
C = 1 element
O = 2 elements
H = 4 elements
O = 2 elements
2 oxygen atoms + 2 oxygen atoms = 4 oxygen atoms total on the products.
All of the elements are balanced.
So the final answer is A: CH4 + 2O2 -> CO2 + 2H2O
Hope it helped!
