During combustion, methane yields carbon dioxide and water. The unbalanced equation for this reaction is: CH4(g) + O2(g) → CO2(g) + H2O(l). What will the mole ratios for the balanced equation be? (What coefficients are needed in order to balance this equation?)

• A. 1 CH4, 2 O2, 2 CO2, 2 H2O
• B. 1 CH4, 2 O2, 1 CO2, 2 H2O
• C. 2 CH4, 3 O2, 2 CO2, 4 H2O
• D. 1 CH4, 2 O2, 1 CO2, 2 H2O

Answer: (B)

Verified step by step guidance

1. Identify the number of each type of atom on both sides of the unbalanced equation: CH4(g) + O2(g) → CO2(g) + H2O(l).
2. Count the atoms for each element in the reactants and products: Reactants: 1 C, 4 H, 2 O; Products: 1 C, 2 H, 3 O.
3. Balance the carbon atoms first. Since there is 1 carbon atom in both CH4 and CO2, the carbon is already balanced.
4. Next, balance the hydrogen atoms. There are 4 hydrogen atoms in CH4 and 2 in H2O. To balance, place a coefficient of 2 in front of H2O, giving 4 hydrogen atoms on both sides.
5. Finally, balance the oxygen atoms. There are 2 oxygen atoms in 2 O2 and 4 in 2 H2O and 1 CO2. Place a coefficient of 2 in front of O2 to balance the oxygen atoms, resulting in the balanced equation: CH4 + 2 O2 → CO2 + 2 H2O.