Chemistry help?

[emt1]

Anyone here good at chemistry?

I need the molar mass of an unknown gas.

A 45.95 gram sample is in a rigid container at 1.086 atm and 229.9K.

 

[aethelbert]

Use the ideal gas law to get the total volume and then divide that by the constant ideal gas volume. Then you have the number of moles and go from there.

 

[emt1]

If someone could begin to walk through the steps, I'd appreciate it.

 

[aethelbert]

If someone could begin to walk through the steps, I'd appreciate it.

Ideal gas law is PV=nRT

First plug in numbers and solve for n to find out your total number of moles.

 

[Cave Man]

Sounds like finals week is here...

 

[emt1]

Ideal gas law is PV=nRT

First plug in numbers and solve for n to find out your total number of moles.

I don't have n or V.

 

[cherry su]

n = 45.95/molar_mass

 

[Telp]

n = 45.95/molar_mass

m/mm=PV/RT

 

[Frisco]

Good luck on your take home test!

 

[aethelbert]

I don't have n or V.

V=22.4n

 

[SLC Flyfishing]

Seems to me like you might have too many unknowns to solve this, but assuming that we can use the molar volume of a gas for V then your molar mass should be 35.65249 g/mol which is pretty close to Chlorine.

The molar volume of a gas is 22.4 liters, so your equation would be:

(1.086 atm)(22.4L)/(0.0821 L*atm/mol*K)(229.9K)=n

n will be your number of moles which works out to be 1.289 mol.

you divide your given mass of 45.95 grams by the 1.29 mol to get a molar mass of 35.62 grams/mol. Chlorine (which is a gas at most temperatures) has a molar mass of 35.45 grams/mol.

But where I think this might all fall apart is that I believe that the stated temperature is just shy of Chlorine's vaporization point. So unless I'm mistaken, at that temperature and pressure, Chlorine should be a solid.



It's been like 3 years since I was in Gen Chem so you'll understand if I'm wrong here.

SLC

 

[Telp]

Molar volume of a gas is only 22.4 L at standard temperature and pressure, I thought...Neither