Molar Mass of Gas: Calculate at 100°C & 26.6 kPa

[kro041193]

please help me resolving this problem :s...what do I have to do , what equations I need to use?
What is the molar mass of a gas if 2.6 L of its gas has a mass of 5.4 g at 100°C and 26.6 kPa?

 

[dacruick]

The ideal gas law.

 

[kro041193]

yes but i mean how can i use it.. i know that the equation is :

N=PV/RT

but i don't really know how to answer the problem with it

 

[dacruick]

okay so calculate the number of moles. Then it looks like what you are left with is the number of moles, and a mass

what is molar mass again?

 

[kro041193]

the molar mass is what is asking

 

[dacruick]

yeah I know that's what you are asking. But do you know what molar mass is? Because if you don't know what it is, that's where I would start my problem solving process

 

[symbolipoint]

You have all the numbers you need; you just need to change temperature into kelvin, and pascals into atomospheres.

 

[kro041193]

aa ok .. and no i don't know

 

[dacruick]

Haha http://en.wikipedia.org/wiki/Molar_mass that is a link for molar mass.

but if you don't know what one of the variables in your problem is, then you should find that out. because it turns out that molar mass is literally how much 1 mole of something weighs. And in units it is grams/mole.

 

[kro041193]

ok thnx