Density and r.m.s of an ideal gas

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Apothem
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Homework Statement



A can which is sealed of a volume 0.035m3 contains an ideal gas with a pressure of 150kPa, at a temperature of 350K.
Calculate the gas density and the root mean squared speed of the gas molecules
(P.S. the molecular mass is stated as 28)

Homework Equations



r.m.s=sqrt(3kT/m) density=molar massxP/RxT

The Attempt at a Solution



So before this I calculated the number of moles: (150x103)*(0.035)/(8.31*350)= 1.81 moles (3.s.f)
The number of molecules: N=n*Na=(1.80...)*(6.023x1023)=1.09x1024 molecules (3.s.f)
The mass of the gas (the molecular mass is stated as 28) mass=n*M=(1.80...)(28)=50.5g (3.s.f)

For r.m.s, do I simply just have to put the mass I just calculated into the equation? For the density, do I just put the molar mass as 28?

Thanks for any help in advance!
 
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Apothem said:

Homework Statement



A can which is sealed of a volume 0.035m3 contains an ideal gas with a pressure of 150kPa, at a temperature of 350K.
Calculate the gas density and the root mean squared speed of the gas molecules


Homework Equations



r.m.s=sqrt(3kT/m) density=molar massxP/RxT

The Attempt at a Solution



So before this I calculated the number of moles: (150x103)*(0.035)/(8.31*350)= 1.81 moles (3.s.f)
The number of molecules: N=n*Na=(1.80...)*(6.023x1023)=1.09x1024 molecules (3.s.f)
The mass of the gas (the molecular mass is stated as 28) mass=n*M=(1.80...)(28)=50.5g (3.s.f)

For r.m.s, do I simply just have to put the mass I just calculated into the equation? For the density, do I just put the molar mass as 28?

Thanks for any help in advance!

It seems like the following should have been put into the Problem Statement:

The mass of the gas (the molecular mass is stated as 28)
 
SteamKing said:
It seems like the following should have been put into the Problem Statement:

Sorry I have added it now.
 
Apothem said:

Homework Statement



A can which is sealed of a volume 0.035m3 contains an ideal gas with a pressure of 150kPa, at a temperature of 350K.
Calculate the gas density and the root mean squared speed of the gas molecules
(P.S. the molecular mass is stated as 28)

Homework Equations



r.m.s=sqrt(3kT/m) density=molar massxP/RxT

The Attempt at a Solution



So before this I calculated the number of moles: (150x103)*(0.035)/(8.31*350)= 1.81 moles (3.s.f)
The number of molecules: N=n*Na=(1.80...)*(6.023x1023)=1.09x1024 molecules (3.s.f)
The mass of the gas (the molecular mass is stated as 28) mass=n*M=(1.80...)(28)=50.5g (3.s.f)

For r.m.s, do I simply just have to put the mass I just calculated into the equation? For the density, do I just put the molar mass as 28?

Thanks for any help in advance!

In the formula for the rms speed, m is the mass of one molecule.

As for the density, you calculated the mass of the gas already: it is 50.5 g. The volume of the gas is given. And you certainly know how the density is defined with mass and volume ?

ehild