Given the enthalpy of vaporization, and the vapour pressure at one temperature, you can predict the vapour pressure at a second temperature. Use the Clausius-Clapeyron.
Thank you for being thorough! My textbook and every other website I looked at for the Clausius-Clapeyron equation assumed I knew how to undo ln and didn't go over it, and I was getting pretty frustrated. You made this equation easy for me to understand and made me laugh in the process. You've earned a new subscriber!
My professor glazed over this and never solved an equation and my book doesn't even discuss this. For the life of me I couldn't remember how to undo the ln(x) and every other online resource just says to undo it without explaining how. Thank you, thank you, thank you!!!!!
THANKS SO MUCH FOR THIS! I have a chem test tomorrow and I was struggling trying to figure out how to undo the ln. Thanks so much for your help! You're a godsend
I always love when some random youtube video I found by googling a subject teaches me more about chemistry in five minutes than my professor does in fifty.
THANK YOU!! I saw other videos but you are the only one who explained how to do away with the "ln". Other people were going right to the answer....so frustrating. Thank you thank you thank you.
Thanks, +ChemistNate! This made much more sense than the LiveScribe I was given by my instructor. I couldn't figure out how to address the ln portion to make it go away. And the T2-T1 parts on my calculator didn't work until I saw how you did it. Thanks for the helpful videos!
You are a life saver bro! There is no way I can thank you enough dude, I've always disliked chemistry because I've had very iffy teachers that just made it very confusing, but you explained it in a way that gets to the point without the confusion idk. either way you rock lol is that offer about test topics still valid?!?!?!?!
Awesome explanation. Answered all my questions as I was working through this equation. and made me laugh! Looks like you posted this a while ago, but hey, thanks very much :)
Hahaha "I got Kelvin...on the bottom of my...whatever. The Kelvins cancel out, just trust me on that." XD He was on the right track! So funny, thank you for making this video entertaining.
Bookmarked the site. I couldn't find a submission tab on the site. Nate, Here is a list of items for my next test. Solve Henry's Law problems, Solve Raout's Law problems, Calculate freezing point depression and/or boiling point elevation. Calculate the osmotic pressure, use osmotic pressure data to calculate molecular weight. Keep up the great work! I loved the video for Eutrophication. Hopefully you continue so that I can use you as a resource for my students.
This equation can also be used to calculate the vapour pressure of a substance inside of a vacuum. I did this also to predict the air density at altitude. Which turned out to be very close, obviously with the make up of the atmosphere it was a challenge but it’s pretty close.
Those are BASICALLY the same equation, because vapour pressure IS a type of equilibrium. This equation is just a simplified version, for one specific process.
Will this give you the vapor pressure at equilibrium? if you have a bowl of liquid water in a sealed container with ambient room temperature which was sealed after exposure to open air for a long time, you can't expect the water to reach 3.64kPa right away. There must be some sort of natural response. Is there a way to figure that out?
For anyone wondering, the Kelvins cancel out because the one on the left was in the denominator of the denominator, which basically means it would go back up to the numerator.
Van hoff is again for one procces. right? i think you use the equation it fits with your data given . If you have pressured given you use clausius-clapeyron and if u have Kp you use van hoff . right?
thank you sir. hope i can see more problem solving in your video. i have a subject right now physical chemistry and its not easy for me to understand only one example. thank you so much this will help me to pass my subject. love it.. we are using physical chemistry book by Moron and Lando.
I just realized that your formula is ln(P1/P2) with ((1/T2)-(1/T1)).. on the formula sheet that my teacher gave me, the formula is ln(P2/P1) with ((1/T2)-(1/T1)) ? Is it wrong? I've been using this formula for my hw D:
agreed kind of stupid thing to say but in fact they cancel because in the expression dH/ 8.314J/mol*K where mol*K are the denominator of the denominator, therefore, the K in the denominator of (1/298K - 1/373K)becomes what we could refer as the numerator and thats why they cancel. also is the same reason why moles of the dHvap cancel with the mole of the R constant
You can write the equation either way. Long as your pressure and temperature correspond. So it can be ln(P2/P1) but your temp will be (1/T1-1/T2) OR ln(P1/P2) WITH (1/T2-1/T1). Hope that makes sense.
The kelvins cancel because kelvins in your R constant are the denominator of a denominator which makes them a numerator and then the other kelvins are in the denominator.
