Preparation and Properties of Oxygen

Correct Answer

📖 Governing Law / Core Concept

Helium is used as a diluent to prevent decompression sickness and reduce nitrogen narcosis in deep-sea diving.

🧪 Step-by-Step Breakdown

Helium (He) is preferred because of its low solubility in blood, compared to nitrogen (N₂). This property reduces the risk of gas embolism during rapid ascent. The use of helium allows divers to safely breathe at depths where pressure significantly increases.

The chemical reaction involved in gas exchange in the lungs is simplified as follows:

🔍 Option Analysis

• A: Chlorine (Cl₂): Toxic and corrosive; not used in diving.
• C: Nitrogen (N₂): Present in air but increases the risk of nitrogen narcosis.
• D: Ozone (O₃): Harmful to lungs; not suitable for breathing mixtures.

⚡ Mnemonic / Speed-Run

Remember: "Helium Helps Divers" to recall that helium is the ideal gas for deep-sea diving.

6. Visual Suggestion

📖 Factual Verification & Reference