Tuesday, November 16, 2010

Ch 12_3 #4

For part a) use equation for ideal gas. Psi is not SI units so you have to convert it into correct units.
For part b) use relationship for energy and temperature and not that you asked to calculate the energy per one atom. Does the number you obtain is very small or big? Does it make sense?

11 comments:

Anonymous said...

It doesn't seem to say the pressure in PSI, it looks like it is in atm already, is that right?

Anonymous said...

I've been working with PV=nRT for a while now, I don't seem to be able to get the answer.

Anonymous said...

i cant get it either, can anyone help?

Prof. Tsybychev said...

Psi is an additional unit pound per square inch 14.7 psi = 1 atm =1.01 x10^5 Pa. Is this what confuse you? In addition you are given a gauge pressure not absolute pressure so you need to convert to SI units first

Prof. Tsybychev said...
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Anonymous said...

I converted psi to kPa, doing 1 psi = 6.895 kPa...then used PV=nRT -> (kPa)(L) = moles * 8.314 * T, then converted T to Kelvin...all those numbers should be correct but im not getting it correct.... I know 8.314 is the one to use because my units are consisted of kPa, L, mole, and K.

Anonymous said...

The temperature I got for Part A was not working so I tried manipulating it. subtract 273 from it to see if that works, it did for me.

Anonymous said...

I converted the gas law to get T=Pv/nR. Since 1psi=6.895kPa my gas was 68psi=468.86kPa. So T=(468.86kPa*16L)/(7.9mol*8.31L*kPa/K*mol)=114.3K-273.15=-158.9C

Did i do something wrong here? it's telling me im wrong!

Anonymous said...

Guys, remember that what you are given is Gauge Pressure. Don't forget to add the atmospheric pressure (14.7 psi, or 101.3 kPa) to the pressure you plug into the equation for your calculations!

Tarun said...
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Tarun said...
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