Question

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?

1.The C₂H₆ gas sample has the largest average kinetic energy.

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

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

4.The mass of the gas in each container is the same.

5. The Xe gas molecules collide with the container walls most frequently.

6. The Xe gas sample has the lowest density.

Answer 1

2)

we know that

PV = nRT

n = PV / RT

here

P , V , R , T are same for all the gases

so

all the gases have same numer of moles

now

number of molecules = moles x 6.023 x 10^23

as moles are same for all gases

number of molecules is also same for all gases

so

statement 2 is false

4)

now

mass = moles x molar mass

here

moles of all gases are same

so

higher the molar mass , higher the mass

so

Xe should have higher mass followed by Cl2 and lastly C2H6

so

mass order is

Xe > Cl2 > C2H6

so

statement 4 is false

6)

now

density = mass / volume

here volume is 1 L for all

so

higher the mass . higher the density

so

the density order is

Xe > Cl2 > C2H6

so

statement 6 is false

1)

we know that

average kinetic energy only depends on temperature

as the temperature is same for all the gases

average kinetic energy is same for all of them

so

statement 1 is false

5)

as C2H6 has lower mass , they have higher velocity

they collide with the container walls most frequnetly

so

statement 5 is false

3)

all have same kinetic energy

but

Xe has the highest mass of all

so

Xe collisons will be more forceful

so

statement 3 is true