Question

What needs to be done to balance this equation?
Responses

Add coefficient 2 to O2 on the left side of the equation.
Add coefficient 2 to uppercase O subscript 2 end subscript on the left side of the equation.

Add coefficient 4 to O2 on the left side of the equation.
Add coefficient 4 to uppercase O subscript 2 end subscript on the left side of the equation.

Remove coefficient 2 in front of H2O on the right side of the equation.
Remove coefficient 2 in front of uppercase H subscript 2 end subscript uppercase O on the right side of the equation.

Do nothing, the equation is already balanced.
Do nothing, the equation is already balanced.
A picture molecules in a chemical reaction with the labels: C H subscript 4 plus O subscript 2 right arrow C O subscript 2 plus 2 H subscript 2 O

Answer 1

Add coefficient 2 to O2 on the left.

Balanced equation: CH4 + 2 O2 → CO2 + 2 H2O

Check (atoms):
- C: 1 left, 1 right
- H: 4 left, 2×2 = 4 right
- O: 2×2 = 4 left, 2 (in CO2) + 2 (in 2 H2O) = 4 right