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: Understanding reactivity with cold water:
When metals react with cold water, they typically form hydroxides and release hydrogen gas. The reactivity of metals with water increases as we move down the alkali metal group (Group 1 of the periodic table), with the reaction becoming more vigorous.

Step 2: Analyzing the metals in the question:
The metals in question are likely to be alkali metals, such as Lithium (Li), Sodium (Na), and Potassium (K). Alkali metals are known for their reactivity with water.

- Lithium (Li) reacts gently with cold water, forming lithium hydroxide and hydrogen gas.
- Sodium (Na) reacts more vigorously than lithium, forming sodium hydroxide and hydrogen gas.
- Potassium (K) is highly reactive and reacts very vigorously with cold water, forming potassium hydroxide and hydrogen gas, and is so reactive that it can even ignite the hydrogen gas produced.

Step 3: Conclusion:
Among the given metals, Potassium is the most reactive towards cold water. Its reaction is more intense than that of Sodium and Lithium, making it the most reactive metal in this case.