A copper penny can be dissolved in nitric acid but not in hydrochloric acid. Using reduction potentials from the book, show why this is so. What are the products of the reaction? Newer pennies contain a mixture of zinc and copper. What happens to the zinc in the penny when the coin is placed in nitric acid? Hydrochloric acid? Support your explanations with data from the book, and include balanced equations for all reactions.

Copper can dissolve in nitric acid because its reduction potential (+0.34 V) is greater than zero, whereas it won't dissolve in hydrochloric acid because it has a lower reduction potential difference with hydrogen (+0.34V) not enough to reduce hydrogen ions to hydrogen gas. The reaction with nitric acid produces copper ions, nitrogen dioxide gas, and water: \( Cu (s) + 4HNO_{3} (aq) \rightarrow Cu(NO_{3})_{2} (aq) + 2NO_{2} (g) + 2H_{2}O (l) \) In newer pennies, zinc reacts with nitric acid, producing zinc ions, nitric oxide gas, and water: \( Zn (s) + 2HNO_{3} (aq) \rightarrow Zn(NO_{3})_{2} (aq) + NO (g) + 2H_{2}O (l) \) Zinc also reacts with hydrochloric acid, dissolving and producing zinc chloride and hydrogen gas: \( Zn (s) + 2HCl (aq) \rightarrow ZnCl_{2} (aq) + H_{2} (g) \) Copper, on the other hand, remains unreacted in hydrochloric acid due to its lower reduction potential difference with hydrogen.