Dalton’s Law of Partial Pressures

When more than one gas is mixed together, the pressure of each individual gas can be calculated by employing the ideal gas law. Expanding on Joseph Louis Proust’s law of definite proportions, John Dalton defined the law of multiple proportions, which quickly led to his law of partial pressures.

First observed by Dalton in 1803, the 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.’ Therefore, to calculate the pressure of a container, one must simply combine the pressures of all the separate gases contained within.

Lee is a freelance writer with a keen interest in history and science.