Question

Both CO₂ and H₂ gases are -

• A. Soluble in water
• B. Colourless
• C. Acidic
• D. Heavier than air

Hint:

Both CO\textsubscript{2} and H\textsubscript{2} are colourless gases, which is a defining characteristic of these gases.

Answer 1

The Correct Option is B

Step 1: Gas Properties of CO₂ and H₂
Carbon dioxide (CO₂) is a colorless gas that forms carbonic acid (H₂CO₃) when dissolved in water.
Hydrogen gas (H₂) is also colorless and exists as a gas in its molecular form.

Step 2: Option Evaluation

• Option 1: Water Solubility: Both gases dissolve in water, but this is not their key characteristic.
• Option 2: Colorless: Both CO₂ and H₂ are colorless; this is the most accurate defining property.
• Option 3: Acidity: CO₂ is acidic in water, but hydrogen gas is neutral.
• Option 4: Heavier than Air: CO₂ is heavier than air, while hydrogen is lighter, making this option incorrect.

Step 3: Conclusion
The most accurate description for both gases is that they are colorless.

Conclusion:

Both gases are colorless.