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Dalton's Law of Partial Pressures Calculator

Calculates the total pressure of a gas mixture as the sum of the partial pressures of its individual components.

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Total Pressure

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Overview

Dalton's Law of Partial Pressures states that in a mixture of non-reacting gases, the total pressure exerted is equal to the sum of the partial pressures of the individual gases. This law is fundamental in understanding the behavior of gas mixtures, particularly in atmospheric chemistry, diving, and industrial processes. It assumes ideal gas behavior and that the gases do not chemically react with each other.

Symbols

Variables

= Partial Pressure of Gas A, = Partial Pressure of Gas B, = Partial Pressure of Gas C, = Total Pressure

Partial Pressure of Gas A
atm
Partial Pressure of Gas B
atm
Partial Pressure of Gas C
atm
Total Pressure
atm

Apply it well

When To Use

When to use: Use this law when dealing with a mixture of gases in a container and you need to find the total pressure, or if you know the total pressure and all but one partial pressure. It's applicable for ideal gas mixtures where components don't react.

Why it matters: This law is crucial for fields like respiratory physiology (understanding gas exchange in lungs), meteorology (atmospheric pressure), and chemical engineering (designing gas separation processes). It helps predict gas behavior in complex systems, ensuring safety and efficiency.

Avoid these traps

Common Mistakes

  • Forgetting to convert units of partial pressures before summing.
  • Applying the law to gases that chemically react with each other.
  • Confusing partial pressure with mole fraction.

One free problem

Practice Problem

A gas mixture contains three non-reacting gases: Gas A, Gas B, and Gas C. Their partial pressures are 0.2 atm, 0.5 atm, and 0.1 atm, respectively. What is the total pressure of the mixture?

Partial Pressure of Gas A0.2 atm
Partial Pressure of Gas B0.5 atm
Partial Pressure of Gas C0.1 atm

Solve for:

Hint: Sum the individual partial pressures.

The full worked solution stays in the interactive walkthrough.

References

Sources

  1. Atkins' Physical Chemistry
  2. Halliday, Resnick, Walker - Fundamentals of Physics
  3. Wikipedia: Dalton's law
  4. Atkins' Physical Chemistry, 11th Edition
  5. IUPAC Gold Book (Compendium of Chemical Terminology)
  6. Halliday, Resnick, and Walker, Fundamentals of Physics, 11th Edition
  7. McQuarrie, Donald A. Physical Chemistry: A Molecular Approach
  8. Brown, Theodore L., H. Eugene LeMay Jr., Bruce E. Bursten, Catherine J. Murphy, Patrick M. Woodward, and Matthew W. Stoltzfus.