A sample of neon effuses from a container in 73 seconds. The same amount of an unknown noble gas requires 149 seconds.
Identify the gas.
The closest would be Krypton, not Radon
Use Graham's law of effusion.
rateX/rateNe= sqrt (molmassNe/molmassx)
solve for mole mass of x.
Now notice this: rate above is volume/time
You are given time. So if you want to plug in the given times, the equation becomes
time1/timeNe=sqrt(molmass1/timeNe)
i am not doing it right , first i got Hydrogen and then Helium...im not sure what im doing wrong
wouldnt the equation be 149/73=sqrt(20.18/molar massx)
No it is inverse
How did you get the 4.16?
149 Ne/73 unknown = sqrt(MM unknown/20.183)
Square root the denominator
2.0411 = sqrt(MM unknown)/ 4.4925
multiply the denominator to isolate the unknown
2.0411 x 4.4925 = sqrt(MM unknown)
9.16972 = sqrt(MM)
Square both sides,
84.083 = unknown molar mass, closest element is the noble gas Radon.
Bleh, I meant Krypton, not Radon.
To identify the unknown noble gas, we can use Graham's law of effusion. According to Graham's law, the rate of effusion of a gas is inversely proportional to the square root of its molar mass.
In this case, we have the rates of effusion for neon and the unknown gas. Let's label the rate of effusion for neon as R1 and the rate of effusion for the unknown gas as R2.
Given that the effusion time for neon is 73 seconds and the effusion time for the unknown gas is 149 seconds, we can set up the following equation:
R1/R2 = √(M2/M1)
where M1 and M2 are the molar masses of neon and the unknown gas, respectively.
Substituting the given values:
73/149 = √(M2/M1)
To find the unknown gas, we can solve this equation for M2/M1.
(73/149)^2 = M2/M1
Calculating this expression:
(0.4906) = M2/M1
Since the molar mass ratio is less than 1, the molar mass of the unknown gas (M2) must be less than the molar mass of neon (M1).
Based on the noble gases in the periodic table, the noble gas with a lower molar mass than neon is helium (He). Therefore, the unknown noble gas is helium (He).
149/73= sqrt(molmassX/20.18)
molmassX=4.16*20.18
The closest Nobel element is Radon.