Gases WS II 13. a) the root mean square velocity of He is greater than that of Kr. This is due to the fact that the molar mass of He is less than Kr. The square root of the molar mass is in the denominator of the equation. Smaller denominator (MM) will yield a higher velocity. B) the temperature must increase in order to increase the avg. speed of atoms.
Diffusion: describes the mixing of gases. The rate of diffusion is the rate of gas mixing. Diffusion
Effusion Passage of gas through a small hole, into a vacuum. The effusion rate measures how fast this happens. Graham’s Law the rate of effusion is inversely proportional to the square root of the mass of its particles.
Effusion: Diffusion: Graham’s Law Rates of Effusion and Diffusion
Gases WS II 14. Two factors that cause deviations are an increase in attractive forces between particles and a reduction in free space relative to the volume of the container. At low T, gas particles are closer and move slower. Forces of attraction exist between gas particles when they are in close proximity and these forces reduce the expected pressure excreted by the gas. Ideal gas law assumes that gas particles don’t have V of their own as it is negligible compared to V of container. When the V occupied by the particles makes up a high percentage of total volume of the container gas does not behave ideally.
Gases WS II 15 Average distance between gas particles increases as P decreases. When particles are further apart attractive forces between particles are greatly reduced. This is why gas particles will behave as they have no interaction with one another. Therefore there is no reduction in the expected pressure due to the forces of attraction between particles.
Gases WS II 16. a) 181 atm b) When gases are behaving ideally there are no forces of attraction. No forces slowing them down before they strike container. We do have forces of attraction when they are close to one another. These attractive forces reduce the expected pressure of the gas. They will pull on the gas particles and cause the reduction in force when they hit the container and therefore reduce the pressure.