Question

The most reactive metal among the following towards cold water is:

• A. Aluminium
• B. Potassium
• C. Sodium
• D. Calcium

Answer 1

The Correct Option is B

Step 1: Reactivity with cold water:
Metals react with cold water to produce hydroxides and hydrogen gas. Reactivity with water increases down Group 1 (alkali metals), with more vigorous reactions.

Step 2: Analyzing specific metals:
The metals are likely alkali metals (e.g., Lithium (Li), Sodium (Na), Potassium (K)), known for their water reactivity.

- Lithium (Li): Reacts gently, forming lithium hydroxide and hydrogen gas.
- Sodium (Na): Reacts more vigorously than lithium, forming sodium hydroxide and hydrogen gas.
- Potassium (K): Highly reactive, reacts very vigorously with cold water, forming potassium hydroxide and hydrogen gas. It can ignite the produced hydrogen gas.

Step 3: Conclusion:
Of the metals discussed, Potassium exhibits the highest reactivity with cold water, surpassing Sodium and Lithium in intensity.