Question

gaseous methane (ch₄) reacts with gaseous oxygen to give gaseous carbon dioxide and gaseous water, producing flame and heat. the correct balanced chemical equation is: 1) ch₄(g) + o(g) → co(g) + h₂o(g) 2) ch₄(g)+ o₃(g) → co₃(g) + h₂o(g) 3) ch₄(g)+ 2o₂(g) → co₂(g) + 2h₂o(g) 4) ch₄(g)+ 3o₂(g) → co₂(g) + 2h₂o(g)

Explanation:

Step1: Check Reactants and Products

Methane ($CH_4$) reacts with oxygen ($O_2$, not $O$ or $O_3$) to form carbon dioxide ($CO_2$) and water ($H_2O$). Eliminate options 1 (uses $O$) and 2 (uses $O_3$ and forms $CO_3$).

Step2: Balance Atoms

• Carbon: 1 in $CH_4$, 1 in $CO_2$ (balanced).
• Hydrogen: 4 in $CH_4$, 2 in $H_2O$ → need 2 $H_2O$ (4 H total).
• Oxygen: Reactants: $O_2$; Products: 2 (from $CO_2$) + 2 (from $2H_2O$) = 4 → need 2 $O_2$ (4 O total).

So equation: $CH_4(g) + 2O_2(g)
ightarrow CO_2(g) + 2H_2O(g)$ (option 3). Option 4 has 3 $O_2$ (6 O), but products have 4 O (imbalanced).

Answer:

1. $CH_4(g) + 2O_2(g)

ightarrow CO_2(g) + 2H_2O(g)$