Lowest Average Speed of Gases at 25C: H2S

[Soaring Crane]

Which of the following gases has the lowest average speed at 25C?
a.NH3
b.O2
c.H2S
d.CH4
Is it H2S? Given the formula sqrt(3RT/M), is it not true that the gas with the greatest molar mass will have the lowest speed?
NH3 = 17.03 g/mol
O2 = 32 g/mol
H2S = 34.08 g/mol
CH4 = 16.04 g/mol
Thanks.

 

[lightgrav]

Yes, the KE of each molecule (at the same Temperature) is the same.
KE = ½ m v^2 = 3/2 k_B T
If you haven't seen it yet, k_B = k_Boltzmann = R/N_Avagadro