Question

Which metals are kept in kerosene?

• A. Na \& K
• B. Zn
• C. Cu
• D. Fe

Hint:

Highly reactive metals like alkali metals (Group 1 elements such as Na and K) are stored under kerosene or paraffin oil to prevent their rapid and dangerous reactions with atmospheric oxygen and moisture. Less reactive metals do not require such specialized storage.

Answer 1

The Correct Option is A

Step 1: Understand the reactivity of metals.
Some metals are highly reactive and readily react with air (oxygen and moisture) and water. To prevent these reactions and ensure their safe storage, they are often stored under a protective layer of a substance that prevents contact with air and moisture. Step 2: Evaluate the reactivity of the given metals.
Sodium (Na) and Potassium (K): These are alkali metals, located in Group 1 of the periodic table. They are extremely reactive metals. They react vigorously with oxygen in the air (even at room temperature, causing them to tarnish rapidly) and violently with water, releasing hydrogen gas which can ignite due to the heat generated. Therefore, they need to be stored in an inert medium.
Zinc (Zn): Zinc is a moderately reactive metal. It reacts with oxygen in the air to form a protective layer of zinc oxide, which prevents further corrosion. It does not react vigorously with water at room temperature.
Copper (Cu): Copper is a relatively unreactive metal. It slowly reacts with atmospheric gases over time to form a greenish patina (copper carbonate), but it does not react with water or oxygen rapidly at room temperature.
Iron (Fe): Iron is a moderately reactive metal. It reacts with oxygen and moisture in the air to form rust (hydrated iron(III) oxide), but this process is slow and does not require storage in kerosene. Step 3: Determine the appropriate storage method.
Kerosene is an organic solvent and does not react with highly reactive metals like sodium and potassium. It acts as a barrier, preventing their contact with air and moisture. Therefore, sodium and potassium are stored in kerosene to prevent their highly exothermic reactions with oxygen and water. $$(1) Na \& K$$