Question

Which of the following metals produces hydrogen gas with cold water?

• A. Copper
• B. Gold
• C. Potassium
• D. Aluminium

Hint:

Alkali metals, such as potassium, react vigorously with cold water to produce hydrogen gas.

Answer 1

The Correct Option is C

When a metal reacts with cold water, hydrogen gas is produced. The ability of a metal to produce hydrogen gas with cold water depends on its reactivity.
Step 1: Behavior of the given metals.
- Copper (Cu) does not react with cold water. It is relatively unreactive with water.
- Gold (Au) is one of the least reactive metals and does not react with cold water to produce hydrogen gas.
- Potassium (K) is an alkali metal and reacts vigorously with cold water to produce hydrogen gas.
- Aluminium (Al) reacts with cold water, but in the presence of air, it forms a protective oxide layer that prevents further reaction unless the oxide layer is removed.
Step 2: Conclusion.
Among the given metals, Potassium reacts with cold water to produce hydrogen gas. The correct answer is (C).