Which of the following unbalanced half-reactions is correctly labeled as an oxidation or reduction? (a) NO₃^- (aq) → NO(g); reduction (b) Zn(s) → Zn²⁺(aq); reduction (c) ClO₃^-(aq) → Cl₂(g); oxidation (d) Br^-(aq) → Br₂(l); reduction

What is the coefficient on Sn²⁺ when the following reaction is balanced in acidic solution?

(a) 2 (b) 4 (c) 5 (d) 7

Balance the redox reaction in basic solution. What is the coefficient on the hydroxide ion, and on which side of the equation does it appear? (a) 2 OH^- in reactants (b) 4 OH^- in products (c) 4 OH^- in reactants (d) 3 OH^- in reactants