Question

Which metal does not react with water to produce hydrogen gas?

• A. Cadmium
• B. Lithium
• C. Potassium
• D. Sodium

Hint:

Compare the reactivity series positions of these four metals.

Answer 1

The Correct Option is A

We are asked which of these four metals fails to liberate hydrogen from water.

1. Potassium is one of the most reactive metals, it reacts explosively with water and gives hydrogen gas.
2. Sodium also reacts vigorously with cold water, forming sodium hydroxide and hydrogen gas.
3. Lithium reacts with water too, though more gently, still producing hydrogen along with lithium hydroxide.
4. Cadmium sits well below hydrogen in the activity series and is unable to displace hydrogen from water under normal conditions.

So the metal that does not react with water to give hydrogen is cadmium, option A.