a typical questions of gases (1 Viewer)

[clicker]

a sample of CO gas was collected over water at 20 degrees and a total pressure of 1.045 atm. if the volume of water collected was 50.0 ml, what was the mass of CO collected ?

(at 20 degrees the vapour pressure of water is 17.5 torr. )

 

[~*HSC 4 life*~]

hmmm bit of a weird question...normally i'd use the "volume of 1 mole ideal gas at RTP = 24.47L/mol" but thats for conditions 1atm presure and 25 deg cels.

your conditions are slightly different though so hmmm, not sure..

i dont really know but i guess i'd just go

1 mole = 24.47 L

.: no moles= 24.47/0.050

then when you calculate this amount, use the
n= m/MM

probably really wrong though

 

[Dreamerish*~]

what does "collected over water" mean?

 

[withoutaface]

The molar mass of water is 18, hence there are 2 7/9 moles in 50 mL's.

I have no idea how to do this question, are you sure it's in the syllabus.

 

[~ ReNcH ~]

Are there standard molar volumes published for such conditions?
If not, how do you work out the molar volume @ 1.045atm and 20^oC?

 

[xiao1985]

17.5 torr = 2.273 e-8 atm... which is very insignificant comparing to the total pressure of 1.045 atm...
does the q ask u to assume that only CO and water vapour are present?!

edit: btw at 20C, 1.045 atm, 1mole of gas = 23.0234 L of volume... saves working out...