Question

Dry ice is also known as _________

• A. Solid water
• B. Solid Freon-12
• C. Solid nitrogen
• D. Solid carbon dioxide

Hint:

Dry ice sublimates directly into carbon dioxide gas, which also helps inhibit the growth of aerobic spoilage bacteria on the surface of packaged foods during transit.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Dry ice is a cooling agent used in food storage, transport, and freezing.
Unlike water ice, it transitions directly from a solid to a gaseous phase without melting into a liquid residue, preventing moisture damage to food packaging.

Step 2: Detailed Explation:
Dry ice is the solid form of carbon dioxide (\(CO_2\)):
- Carbon dioxide is a gas at room temperature and atmospheric pressure.
- When carbon dioxide gas is liquefied under pressure and then allowed to expand rapidly, it cools and solidifies into dry ice snow, which is then compressed into blocks or pellets.
- At normal atmospheric pressure, dry ice has a surface temperature of \(-78.5^\circ\text{C}\).
- It undergoes sublimation, passing directly from the solid phase to the gaseous phase.
This property makes it highly useful for preserving frozen foods during transport, as it keeps products cold without leaving liquid residue that could damage packaging or promote microbial growth.
- Solid water is conventiol ice, solid Freon-12 is a synthetic refrigerant, and solid nitrogen exists only at extremely low temperatures below \(-210^\circ\text{C}\).

Step 3: Fil Answer:
Dry ice is the solid state of carbon dioxide.
Hence, the correct option is (D).