What's the rms speed of the molecules?

AI Thread Summary
To calculate the root mean square (rms) speed of molecules in a gas canister, the ideal gas law (PV=nRT) can be utilized without needing the temperature directly. The discussion emphasizes that nm, representing the total mass of the gas, is derived from the number of moles multiplied by the molar mass. The rms speed can be calculated using the formula v = sqrt(3kT/m), where k is Boltzmann's constant and m is the mass of a molecule. Ultimately, the conversation centers on deriving the necessary variables to compute the rms speed effectively. Understanding the relationships between pressure, volume, and mass is crucial for solving this problem.
cdymdcool
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1. A canister containing 150kg of an ideal gas has a volume of 8 m^3. If the gas exerts a pressure of 5*10^5 Pa, what's the rms speed of the modecules?



I can't get the temperature of the canister...
 
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You don't need it. You have PV=nRT, so T=PV/nR. Leave it as that and continue solving the problem. Eventually, you should get a "nm" in your solution. What's this equal to?
 
so nm equals the #of moles times its mass, what isn't the #of moles still unknow?
 
nm is the #of moles times the molar mass (mass per mole). What's # of moles times the mass per mole?
 
ideasrule said:
nm is the #of moles times the molar mass (mass per mole). What's # of moles times the mass per mole?

I use the formula v = square root of(3kT/m), which k stands for boltzmann's constant and m stants for the mass of molecule.
 

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