Question

I WILL MEDAL
Consider separate 1.0 L samples of the following gases at STP: Cl2, C2H6, and Xe.
Which of the following statements are true regarding these gas samples?


The mass of the gas in each container is different.

The C2H6 gas molecules collide with the container walls most frequently.

The Xe gas sample has the most molecules of gas present.

The Xe gas sample has the highest density.

Each Xe gas particle collision with the container wall is more forceful as compared to each C2H6 and Cl2 collision.

The C2H6 gas sample has the largest average kinetic energy.

Answer 1

I know the first one is true. I don't know about the others

Answer 2

@zepdrix

Answer 3

@cooltowl 1 mol of every gas occupies 22.4 liters at STP

Answer 4

How does 22.4 L help me understand collisions, density etc?

Answer 5

For an ideal gas, the kinetic molecular theory assumes that the average kinetic energy of a gas sample depends only on the Kelvin temperature (KEavg = 3RT/2). Since P, T, and V are the same values for each gas sample, the moles of gas present must be the same in each gas sample. The most dense gas sample will have the largest mass of gas present in the 1.0 L sample. In general, the lighter the gas molecule the faster the average velocity. Since the smaller gas particles hit the container walls more frequently, the heavier gas molecules must have more forceful collisions in order for the pressure to be the same in each gas sample.
THIS IS THE INFORMATION I WAS GIVEN WHEN I GOT IT WRONG.

Answer 6

You know it's STP so I think


1 mol/(22.4L) = (X moles)/(1liter)

You have the same number of moles of gas. For each of them. Because the law states at stp 1 mole of every gas occupies the same volume.

I agree with this part

Answer 7

But remember the average kinetic energy or temperature is the same for all these gases.

Answer 8

The number of moles is the same but not the masses of the gases