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Tuesday, November 16, 2010
Ch 12_3 #3
Use the same formula as before, but remember that nitrogen is diatomic gas and thus you have to use correct molar mass.
9 comments:
Anonymous
said...
I am squaring the speed, 35, then multiplying that by the mass, 28, then dividing by 2 in order to get the KE. Once I have that I multiply it by (2/3) then divide by k, 1.38*10^-23. That should Give me Tk but I am repetedly getting the same wrong answer. Does anybody see what I am doing wrong?
Thanks. I changed the molar mass to .0282(kg) and I got a different answer but it was still not right. I am getting a very large positive number and I think the answer should be a very Cold temperature. I don't know what to do differently. Has anybody gotten this one yet?
28 is atomic unit but in this case you need to use SI units i.e. kg for a Nitrogen molecule (since this is what you dealing with) find a kinetci energy, then you calculate temperature. Note that this velocity is very small for molecules/atoms so you temperature should be low.
I converted the 28 amu of N2 gas to kg by multiplying it by 1.66*10^27 and i am getting a low temp but i'm still getting it wrong. What am I doing wrong?
"I converted the 28 amu of N2 gas to kg by multiplying it by 1.66*10^27 and i am getting a low temp but i'm still getting it wrong. What am I doing wrong?"
--> avogadro's number is 1.66*10^-27 you should get the right answer now if you use the vrms equation. The temp will be less than 1 K
We did a similar problem today in class we were asked to find a kinetic energy and the rms velocity. Now you are given rms velocity, thus find kinetic energy, and from it calculate the temperature. Look at today lecture notes.
9 comments:
I am squaring the speed, 35, then multiplying that by the mass, 28, then dividing by 2 in order to get the KE. Once I have that I multiply it by (2/3) then divide by k, 1.38*10^-23. That should Give me Tk but I am repetedly getting the same wrong answer. Does anybody see what I am doing wrong?
make sure everything is in SI including molar mass
Thanks. I changed the molar mass to .0282(kg) and I got a different answer but it was still not right. I am getting a very large positive number and I think the answer should be a very Cold temperature. I don't know what to do differently. Has anybody gotten this one yet?
28 is atomic unit but in this case you need to use SI units i.e. kg for a Nitrogen molecule (since this is what you dealing with) find a kinetci energy, then you calculate temperature. Note that this velocity is very small for molecules/atoms so you temperature should be low.
I converted the 28 amu of N2 gas to kg by multiplying it by 1.66*10^27 and i am getting a low temp but i'm still getting it wrong. What am I doing wrong?
I played around with the answer I got from using just a single atom of N and my answer was near that. What the fuck?
"I converted the 28 amu of N2 gas to kg by multiplying it by 1.66*10^27 and i am getting a low temp but i'm still getting it wrong. What am I doing wrong?"
--> avogadro's number is 1.66*10^-27
you should get the right answer now if you use the vrms equation. The temp will be less than 1 K
T = (m * v^2) / 3k
We did a similar problem today in class we were asked to find a kinetic energy and the rms velocity. Now you are given rms velocity, thus find kinetic energy, and from it calculate the temperature. Look at today lecture notes.
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