Question Detail

Balanced half-reactions: Al + 4OH⁻ → Al(OH)₄⁻ + 3e⁻ and 2H₂O + 2e⁻ → H₂ + 2OH⁻. Multiply to balance electrons: 2Al + 8OH⁻ → 2Al(OH)₄⁻ + 6e⁻ and 6H₂O + 6e⁻ → 3H₂ + 6OH⁻. Combined: 2Al + 2OH⁻ + 6H₂O → 2Al(OH)₄⁻ + 3H₂. The coefficient for H₂O is 6. The options are 1,2,3,4. This suggests a different balancing. A simpler balanced equation: 2Al + 2OH⁻ + 6H₂O → 2Al(OH)₄⁻ + 3H₂. The coefficient for H₂O is 6. Since 6 is not an option, the intended might be a different product. Re-evaluating, common balanced equation: 2Al + 2OH⁻ + 2H₂O → 2AlO₂⁻ + 3H₂. Then H₂O coefficient is 2. Based on the options, 2 is the most likely correct answer.