[Sis290025]

Which of the following gases has the lowest average speed at 25 C?
 
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.  

 

[Donaldson Tan]

choose the substance with the heaviest molecular mass.

so your answer is right