Which of the following metals reacts with cold water?

The correct answer is Sodium.

Key Points

• Sodium reacts vigorously with cold water to produce sodium hydroxide (NaOH) and hydrogen gas (H₂).
• The reaction is highly exothermic, meaning it releases a significant amount of heat.
• Because of its vigorous reaction with water, sodium is stored in kerosene or mineral oil to prevent it from coming into contact with moisture.
• In the reactivity series of metals, sodium is placed higher up, indicating its high reactivity.

Additional Information

• Reactivity Series: This is a series of metals arranged in order of decreasing reactivity. The most reactive metals are at the top, and the least reactive are at the bottom.
• Exothermic Reaction: A chemical reaction that releases energy by light or heat. It is the opposite of an endothermic reaction.
• Sodium Hydroxide (NaOH): Also known as caustic soda or lye, it is a highly caustic metallic base and alkali salt used in many industrial processes.
• Hydrogen Gas (H₂): The lightest and most abundant chemical substance in the universe, hydrogen gas is highly flammable and is used in various industrial applications.
• Storage of Sodium: Due to its high reactivity with water and air, sodium is stored under oil to prevent accidental reactions.