a. 627.1 m/s 
 b. the rate of effusion of ethane = 1.7 faster than hexane
 
Further explanation 
Given 
 T = 200 + 273 = 473 K 
 Required 
 a. the gas speed
 b. The rate of effusion comparison 
 Solution 
 
a. 
 Average velocities of gases can be expressed as root-mean-square averages. (V rms) 
 
 
 
 
R = gas constant, T = temperature, Mm = molar mass of the gas particles 
 From the question 
 R = 8,314 J / mol K 
 T = temperature 
 Mm = molar mass, kg / mol 
 Molar mass of Ethane = 30 g/mol = 0.03 kg/mol 

 
b. the effusion rates of two gases = the square root of the inverse of their molar masses: 

 
M₁ = molar mass ethane =30 
 M₂ = molar mass hexane = 86

 the rate of effusion of ethane = 1.7 faster than hexane