Question

The element producing hydrogen gas with cold water is:

• A. Au
• B. Ag
• C. K
• D. Cu

Hint:

Highly reactive metals like potassium, sodium, and calcium react with cold water to produce hydrogen gas.

Answer 1

The Correct Option is C

Potassium (K) is a highly reactive alkali metal that reacts vigorously with cold water to form potassium hydroxide (KOH) and hydrogen gas (Hâ‚‚). This reaction releases heat and produces bubbles of hydrogen gas. \[ 2K + 2H_2O \rightarrow 2KOH + H_2 \]