I forgot to add: relative humidity is "what percent of full (of water) is this air?" Saturated water vapor pressure means 100% humidity. If the temperature drops, the air can't hold as much water, and you get dew--or frost if it is cold enough!
I'm not familiar with that, sorry. That might be covered in Physical Chemistry or Inorganic Chemistry. Googling gave me this link, which might help you: geo.libretexts.org/Bookshelves/Meteorology_and_Climate_Science/Practical_Meteorology_(Stull)/04%3A_Water_Vapor/4.00%3A_Vapor_Pressure_at_Saturation
Nice video. It would be good to see one where you go into detail about the equation (ideal gas law..?). I am currently making a CPC (Condensation Particle Counter). The vapour chamber is technically "open" to the atmosphere. How does this effect the vapour pressure?
Hi Robert, thanks for the great explanation. What I still don't understand is the concept of vapor pressure within an air parcel. For example, an isolated air parcel warmer than its surroundings will rise, as it rises the parcel expands and the temperature start dropping. What happens in terms of water pressure there? I know it'll be more likely to form liquid water since molecules will slow down as temperature/internal energy decreases, but I can't link this concept if I think what happens with water vapor since there's no body of liquid water at the beginning when air parcel start rising.
I think what you mean is that as the air cools, its capacity to hold water decreases, so the percent humidity climbs, and once it passes 100% you get condensation--clouds, dew, rain, etc. Basically the saturated vapor pressure drops with the temperature, and when the saturated vapor pressure drops become the actual vapor pressure, you get the condensation.
It's a property of water. There's a whole table of numbers for the saturated vapor pressure of H2O at different temperatures. When the temp reaches 100 degrees celsius, the saturated vapor pressure is 760 torr, one atmosphere. Practically speaking, it's a number you have to look up for your specific temperature.
@@robertcruikshank4501Can I derive that data table from an adjusted PV=nRT? I’m trying to calibrate the “absolute humidity” on a sensor I have at home (gm⁻³). Presumably n=m/18 etc?
Good job. Clear and to the point!
Best explanation I've seen of saturated vapor pressure. After watching this video actually things got cleared.
You, my friend, are a lifesaver. Thank you, great explanation
Happy to help!
Best explanation I've seen of saturated vapor pressure. Thank you for taking the time to make this video!
From a nurse anesthesia student, THANK YOU! I love how you explained this
You're welcome! Glad it helped.
I forgot to add: relative humidity is "what percent of full (of water) is this air?" Saturated water vapor pressure means 100% humidity. If the temperature drops, the air can't hold as much water, and you get dew--or frost if it is cold enough!
Ah I now understand, I was confused between the different "types" of pressure before finding this video - thanks a lot!
Happy to help!
This really helped me understand better, thanks!
That was very well explained ,Thank you Sir.
Glad you liked it. You're welcome!
Really clear explanation. By the way, can you explain the exponential relationship between temperature and the saturated vapor pressure?
I'm not familiar with that, sorry. That might be covered in Physical Chemistry or Inorganic Chemistry. Googling gave me this link, which might help you: geo.libretexts.org/Bookshelves/Meteorology_and_Climate_Science/Practical_Meteorology_(Stull)/04%3A_Water_Vapor/4.00%3A_Vapor_Pressure_at_Saturation
Thanks, it helps me a lot
this made perfect sense
nice efficient explanation. thank you.
Glad it was helpful!
Thanks.
Thank you sir for your explanation
You are quite welcome. I'm glad it was helpful!
Nice video. It would be good to see one where you go into detail about the equation (ideal gas law..?).
I am currently making a CPC (Condensation Particle Counter). The vapour chamber is technically "open" to the atmosphere. How does this effect the vapour pressure?
Hi Robert, thanks for the great explanation. What I still don't understand is the concept of vapor pressure within an air parcel. For example, an isolated air parcel warmer than its surroundings will rise, as it rises the parcel expands and the temperature start dropping. What happens in terms of water pressure there? I know it'll be more likely to form liquid water since molecules will slow down as temperature/internal energy decreases, but I can't link this concept if I think what happens with water vapor since there's no body of liquid water at the beginning when air parcel start rising.
I think what you mean is that as the air cools, its capacity to hold water decreases, so the percent humidity climbs, and once it passes 100% you get condensation--clouds, dew, rain, etc. Basically the saturated vapor pressure drops with the temperature, and when the saturated vapor pressure drops become the actual vapor pressure, you get the condensation.
Thank you so much.
You're welcome! A lot of people seem to have trouble with this concept.
Please also explain the concepts of solution thermodynamics ???
I have this: th-cam.com/video/aAr-wN9cGJ0/w-d-xo.html
And this: th-cam.com/video/XZ3FtnNzF8c/w-d-xo.html
I'll see what else I can make.
Where did the 23.76 torr come from?
It's a property of water. There's a whole table of numbers for the saturated vapor pressure of H2O at different temperatures. When the temp reaches 100 degrees celsius, the saturated vapor pressure is 760 torr, one atmosphere. Practically speaking, it's a number you have to look up for your specific temperature.
@@robertcruikshank4501Can I derive that data table from an adjusted PV=nRT? I’m trying to calibrate the “absolute humidity” on a sensor I have at home (gm⁻³). Presumably n=m/18 etc?
@ I found the Clausius-Clapeyron equation.
perfect, thanks!
You're welcome!
Brilliant
Thank you! Glad you liked it!