Sodium is a reactive metal, which if kept open reacts with ___________ to explode and catch fire.

Correct option is C

The correct answer is (c) Oxygen

Explanation:

Sodium (Na) is a highly reactive metal, and if left exposed to air, it reacts with oxygen (O₂) and moisture to form sodium oxide (Na₂O) or sodium hydroxide (NaOH).

• This reaction releases heat, which can ignite sodium, causing it to catch fire or even explode.
• To prevent this, sodium is stored in kerosene or oil, which prevents contact with air and moisture.

Information Booster:

Reaction of Sodium with Oxygen:

​$$4Na + O₂ \rightarrow 2Na₂O$$​​

(Sodium reacts with oxygen to form sodium oxide.)

If moisture is present, sodium oxide reacts with water to form sodium hydroxide:

​$$Na₂O + H₂O \rightarrow 2NaOH$$​

(Sodium hydroxide is highly corrosive and can cause burns.)

Precautions for Handling Sodium:

• Stored in kerosene or mineral oil to prevent reaction with air.
• Handled with forceps and not with bare hands to avoid burns.
• Kept away from water to prevent hazardous reactions.

Additional Knowledge:

• Sodium does not react directly with hydrogen gas to cause fire. However, sodium reacts with water to release hydrogen gas, which may ignite.
• Sodium does not react easily with nitrogen at room temperature.
• Sodium and phosphorus do not react violently when exposed to air.