What typically occurs when a metal is placed into an acidic solution?

• A. The metal remains unchanged and does not react.
• B. The metal forms a precipitate with the acid.
• C. The metal dissolves without any gas being produced.
• D. The metal reacts with the acid to produce hydrogen gas.

Answer: (D)

Verified step by step guidance

1. Understand that when a metal is placed into an acidic solution, a chemical reaction often occurs between the metal and the acid.
2. Recall that many metals react with acids to produce a salt and hydrogen gas. This is a classic single displacement reaction.
3. Write the general reaction equation for a metal (M) reacting with an acid (HA): \[\text{M} + 2\text{HA} \rightarrow \text{M}A_2 + \text{H}_2\] where \[\text{M}A_2\] represents the metal salt formed and \[\text{H}_2\] is hydrogen gas.
4. Recognize that the production of hydrogen gas is a key indicator of this reaction, which can be observed as bubbling or fizzing in the solution.
5. Conclude that the metal does not remain unchanged, nor does it typically form a precipitate with the acid; instead, it dissolves by reacting and releasing hydrogen gas.