Which of the following is the correctly balanced chemical equation for the reaction: Ag(s) + CN⁻(aq) + O₂(g) → Ag(CN)₂⁻(aq)?

• A. 4 Ag(s) + 8 CN⁻(aq) + O₂(g) + 2 H₂O(l) → 4 Ag(CN)₂⁻(aq) + 4 OH⁻(aq)
• B. 4 Ag(s) + 8 CN⁻(aq) + O₂(g) → 4 Ag(CN)₂⁻(aq)
• C. 2 Ag(s) + 4 CN⁻(aq) + O₂(g) → 2 Ag(CN)₂⁻(aq)
• D. Ag(s) + 2 CN⁻(aq) + O₂(g) → Ag(CN)₂⁻(aq) + O₂(g)

Answer: (A)

Verified step by step guidance

1. Identify the species involved in the reaction: solid silver (Ag), cyanide ion (CN⁻), oxygen gas (O₂), and the complex ion silver dicyanide (Ag(CN)₂⁻).
2. Write the unbalanced chemical equation: \(\mathrm{Ag(s) + CN^- (aq) + O_2 (g) \rightarrow Ag(CN)_2^- (aq)}\).
3. Balance the silver (Ag) atoms first by ensuring the number of Ag atoms on the reactant side equals those in the product complex ion. Since each complex contains 1 Ag, multiply accordingly.
4. Balance the cyanide ions (CN⁻) next, noting that each complex ion contains 2 CN⁻ ions, so multiply CN⁻ accordingly to match the number of complex ions formed.
5. Balance oxygen and hydrogen by considering the involvement of \(\mathrm{O_2}\) and water (\(\mathrm{H_2O}\)) if necessary, and balance hydroxide ions (\(\mathrm{OH^-}\)) to ensure charge and atom balance, resulting in the fully balanced equation.