Question

Two identical cylinders contain helium at 2.5 atm and argon at 1 atm respectively. If both the gases are filled in one of the cylinders, the pressure would be:

• A. 3.5 atm
• B. 1.50 atm
• C. 1.75 atm
• D. 1 atm

Hint:

When gases from equal volumes at same temperature are combined into one of them, pressures simply add.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
According to Dalton's Law of Partial Pressures, the total pressure exerted by a mixture of non-reacting gases in a container is equal to the sum of the partial pressures of the individual gases.
: Key Formula or Approach:
\[ P_{total} = P_1 + P_2 \]
This assumes the volume and temperature remain constant.
Step 2: Detailed Explanation:
Given:
Initial pressure of Helium, \( P_{He} = 2.5 \text{ atm} \).
Initial pressure of Argon, \( P_{Ar} = 1 \text{ atm} \).
The cylinders are identical, meaning their volumes are the same.
When both gases are transferred into one of these cylinders, the final volume remains the same as the initial volume of one cylinder.
Assuming no temperature change occurs:
\[ P_{total} = P_{He} + P_{Ar} \]
\[ P_{total} = 2.5 \text{ atm} + 1 \text{ atm} = 3.5 \text{ atm} \]
Step 3: Final Answer:
The final pressure in the cylinder will be 3.5 atm.