Which of the following elements will react spontaneously with 1.0 M HCl(aq) at room temperature?

• A. Au
• B. Ag
• C. Cu
• D. Zn

Answer: (D)

Verified step by step guidance

1. Understand that a metal will react spontaneously with 1.0 M HCl(aq) if it is more reactive than hydrogen in the activity series of metals. This means the metal must be able to displace hydrogen ions (H\textsuperscript{+}) from the acid to produce hydrogen gas (H\textsubscript{2}).
2. Recall the activity series of metals, which ranks metals by their tendency to lose electrons and form positive ions. Metals above hydrogen in this series will react with acids like HCl, while those below will not.
3. Identify the positions of Au (gold), Ag (silver), Cu (copper), and Zn (zinc) in the activity series. Zn is above hydrogen, meaning it can displace H\textsuperscript{+} ions and react with HCl, while Au, Ag, and Cu are below hydrogen and will not react spontaneously.
4. Write the general reaction for a metal reacting with hydrochloric acid: \(\mathrm{M (s) + 2HCl (aq) \rightarrow MCl_2 (aq) + H_2 (g)}\), where M is a metal above hydrogen in the activity series.
5. Conclude that since Zn is above hydrogen, it will react spontaneously with 1.0 M HCl at room temperature, producing zinc chloride and hydrogen gas, whereas Au, Ag, and Cu will not react under these conditions.