Question

1. In two flasks of equal volume, sample A contains CO2 at 0 degrees C and 3.00 atm and sample B contains H2 at 0 degrees celcius and 2.00 atm. Which gas, if either, has

a) molecules with higher average kinetic energies?

b) more molecules?

Answer 1

A:

T = 0C or 273

P = 3 atm

MW = 44 of CO2

B:

T = 0 or 273 K

P = 2 atm

MW = 2 of H2

in general:

Rate H2 /Rate CO2 = sqrt(MWCO2 / MWH2)

expect higher average kinetic energies for H2, since it is a small mass, therefore higher speed/velocitiy.

a)

molecules with higher AVERAGE kinetic energies

b)

more molecules

PV = nRT

n = PV/(RT)

n1 = (P1*V1)/(R*T1)

If P is lower, then expect les moles of CO2

n2 = (P2*V2)/(R*T2)

If P is higher, then expect more moles of H2

More moles --> H2