What is dry ice?

Question

What is dry ice?

1. A. Liquid Nitrogen
2. B. Water ice
3. C. Solid Carbon dioxide (Correct answer)
4. D. Frozen ethanol

Correct Answer

Option C — Solid Carbon dioxide

Detailed Solution & Explanation

The correct answer is Solid Carbon dioxide.

Key Points

• Dry ice is the solid form of carbon dioxide (CO₂) at −78.5°C. It sublimates directly from solid to gas at atmospheric pressure, making it useful for cooling without leaving liquid residue.

Additional Information

• Dry ice is solid carbon dioxide at about −78.5 °C. It sublimates — passing straight from solid to gas — which is why it leaves no liquid.
• That makes it useful for transporting frozen goods and for stage fog, where the cold gas condenses water vapour from the air.
• Other substances that sublime: iodine, camphor, naphthalene and ammonium chloride.
• It must be handled with gloves: contact causes cold burns, and in a closed space the gas displaces oxygen.