How does Dalton’s law of partial pressures help us with our model of ideal gases? That is, what postulates of the kinetic molecular theory does it support?

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 individual gases. Mathematically, it is expressed as: \[P_{total} = P_1 + P_2 + P_3 +...+ P_n\] Where \(P_{total}\) is the total pressure of the gas mixture, and \(P_1, P_2, P_3,..., P_n\) are the partial pressures of individual gases in the mixture.

The Kinetic Molecular Theory is a model which describes the behavior of ideal gases. The theory is based on several postulates, which include: 1. Gases consist of a large number of particles (atoms or molecules) that are in constant random motion. 2. The volume occupied by the gas particles themselves is negligible compared to the volume of the container. 3. Gas particles are neither attracted nor repelled by each other and their collisions are perfectly elastic. 4. The average kinetic energy of gas particles is directly proportional to the temperature of the gas.

Dalton's Law of Partial Pressures supports the following postulates of the Kinetic Molecular Theory: Postulate 1: The constant random motion of gas particles in a mixture means that each gas exerts pressure on the container walls independently. This justifies the additivity of the partial pressures in Dalton's Law. Postulate 3: Since gas particles in a mixture are neither attracted nor repelled by each other, each gas behaves independently and its contribution to the total pressure is unaffected by the presence of other gases. Therefore, Dalton's Law of Partial Pressures supports the first and third postulates of the Kinetic Molecular Theory by showing that individual gases in a mixture behave independently and that their properties can be added together to determine the properties of the mixture as a whole.