Dalton’s law of partial pressures

Definition

Dalton's law of partial pressures states that the total pressure exerted by a mixture of non-reacting gases is equal to the sum of the partial pressures of each individual gas. Each gas in a mixture acts independently and contributes to the total pressure proportionally to its amount.

5 Must Know Facts For Your Next Test

1. Dalton's law can be expressed mathematically as $P_{total} = P_1 + P_2 + ... + P_n$, where $P_i$ represents the partial pressure of each gas.
2. The partial pressure of a gas is proportional to its mole fraction in the mixture.
3. Dalton's law assumes ideal gas behavior, meaning it works best under low pressure and high temperature conditions.
4. The law is crucial for understanding how gases behave in closed systems, like in chemical reactions and biological processes involving respiration.
5. It simplifies calculations involving gas mixtures by allowing each gas to be treated separately.

Review Questions

• How does Dalton's law of partial pressures help in calculating the total pressure of a gas mixture?
• What assumptions are made about gases when applying Dalton's law?
• How do you calculate the partial pressure of a single gas in a mixture?

Related terms

Ideal Gas Law: A relation between pressure, volume, temperature, and number of moles for an ideal gas given by $PV = nRT$.

Mole Fraction: The ratio of moles of one component to the total moles in a mixture.

Kinetic Theory of Gases: A theory that describes gases as collections of small particles in random motion, providing insights into properties like pressure and temperature.