Question

A container contains equal masses of H$_{2}$, He, CO$_{2}$ and Ne at a certain temperature. Which of the following gases exerts minimum partial pressure?

• A. H$_{2}$
• B. He
• C. CO$_{2}$
• D. Ne

Hint:

For equal masses: Heavier gas = Fewer moles = Lower partial pressure.

Answer 1

The Correct Option is C

Step 1: Formula
Partial pressure $P_i \propto$ number of moles ($n_i$). Since masses ($m$) are equal, $n_i = \frac{m}{M_i}$.
Step 2: Molar Mass Comparison
- $H_2$: 2 g/mol - $He$: 4 g/mol - $Ne$: 20 g/mol - $CO_2$: 44 g/mol
Step 3: Analysis
$P_i \propto \frac{1}{M_i}$. The gas with the **highest** molar mass will have the **lowest** number of moles and thus the **minimum** partial pressure.
Step 4: Conclusion
$CO_2$ has the highest molar mass (44), so it exerts the minimum pressure.
Final Answer:(C)