Question

According to Dalton's law of partial pressures, the total pressure of a gas mixture is equal to:

• A. Average pressure of all gases
• B. Sum of partial pressures of individual gases
• C. Product of mole fractions and pressure
• D. Pressure of the heaviest gas

Hint:

Memory Tip: Dalton's law means Total = Addition of individual gas pressures.

Answer 1

The Correct Option is B

Concept:
Dalton's Law of Partial Pressures states that when non-reacting gases are mixed in a container, each gas exerts its own pressure independently. The total pressure of the mixture is the sum of all these individual pressures.

Step 1:
Partial pressure is the pressure exerted by a single gas in a mixture as if it alone occupied the entire container.

Step 2:
If gases have partial pressures $P_1, P_2, P_3, \dots$, then total pressure is: $$P_{\text{total}} = P_1 + P_2 + P_3 + \cdots$$

Step 3:
The option that matches the law exactly is the sum of partial pressures of all individual gases.

Step 4:
Average pressure is not used, product of mole fractions is incorrect here, and pressure does not depend on the heaviest gas alone.