Water vapor Definition and 67 Threads

I found an opinion that TPW (kg/m2) and PWV (mm) are the same thing, but I only found that kg/m2 = 1 mm and did not find any sources confirming that TPW=PWV. How valid is this? And if they are different things, how do you calculate PWV? P.S. In general, I need to get the PWV from the data of...

Hello, I learned recently about alveolar surface tension, and the explanation provided in the course was not satisfactory, it said that it is due to the force that pushes water molecules of the outer layer to the inner layers, I don't understand why this force that pushes water toward the cell...

Hi, I've been thinking about the solution for cleaning a water-cooled gas cooler and would love to hear some advice from the smarter people with more experience. Description - I will try to roughly explain the concept. Gas Cooler is used to decrease exhaust gas temperature. The exhaust gas...

Hello, At my work I came up with the following question: Say we have a vacuum chamber. Inside the vacuum chamber we have at the bottom a water bath. The rest of the chamber is filled with a air and water vapor mixture. The whole system is placed in a room, is at room temperature and is in...

Why can a shock wave condensate water droplets in the air and produce the visible vapor cone that we see when objects move faster than the speed of sound. Also, does this condensation happens only when the object is moving with a velocity greater than sound velocity? I don't understand the...

Building visibiity sensor... What is best angle to detect water vapor reflection from laser, and refraction? I plan to have two open cylindrical containers painted flat black and put inside each other so the overlap is about 0.5-1" (adj to limit ambient light vs airflow). Laser is cheap red...

Hello 4m3/min is 240m3 /hr. Temperature is 293K, at 25C the amount of water is 22.8g/m3 and at 20C it is 17.1g/m3. Relative humidity is 70% and absolute pressure 9bar. Solution: @ 25C relative humidity lowers the water content from 22.8 to 15,96g/m3 so in total 3830.4g/hr 240m3 or air is...

Hi everyone! Terahertz time-domain spectroscopy (THz-TDS) is a spectroscopic technique that is using the radiation in the THz range. https://en.wikipedia.org/wiki/Terahertz_time-domain_spectroscopy A THz-TDS setup consists of an emitter and detector. The emitter creates a short broadband...

So I understand generally how humidity in atmospherics work but there's this one thing I can't reconcile with the fundamentals. First, my understanding of the basics. Water boils at 212 F @ 14.7 psia (1 ATM). At 213F @ 14.7 psia that water is now 1F superheated vapor. So we're all on the same...

I am searching for images of the daytime sky taken within the water vapor absorption bands at 940nm, 1600 nm, 1860 nm, 2700 nm or 2900 nm. Specifically I am trying to see if multispectral images of in-band and adjacent out-of-band photos could be subtracted to show areas of slight water vapor...

If water vapor is pulled inwards and cooled at a fast enough rate could if be frozen back into a solid form? i understand that they would have to be froze together as soon as contact is made but if this is possible what would the temperature have to be? And could this be the only thing that can...

Hello Homework Statement Lets say i have the given parameters: air volume flow : V = 36 m3/h Relative humidity: RH=33% air mixing ratio : X = 5.5 (1g H2O) / 1kg (DRY AIR) (calculated from RH) air temperature : T= 20 C So i know how much mass of water is the air compared to the air's "dry air"...

Whilst I was thinking of hydrogen combustion jet engines. I thought of a little idea... What if you could create thrust with water vapor the same way you could with the exhaust gas of a jet engine. (NOTE: I have no experience in engineering and I only have a mild interest in it). If this is...

Say we have a tire filled with air (equal to ambient air surrounding it in every way). pressure on the gauge is 0. Then, we pressurize it to 1 ATM (15psi). If we heat the tire , the air will be heated and expand based on gas law, or is there a factor that changes it based on the air's...

I have a doubt regarding gibbs phase rule in thermodynamics.. It says the number of independent intensive properties required to specify the state of a system is F=C-P+2 where C is number of components and P is the number of phase.. So for a water and water vapour system, C=1, P=2 . So F=1. If...

Homework Statement How many degrees of freedom does water vapor have Homework Equations Translational up to 3 rotational up to 3 Vibration up to 6 The Attempt at a Solution Well I said water vapor had 3 translational. It can move along the x, y, or z axis I said it had 2 rotational (the...

Hi There, I am trying to understand if I have a vacuum in the below scenario or simply just really low pressure. A pump supplies a pipe with a constant supply of water at one end (Point A) the water discharges several kilometers away at some lower elevation (Point B). At "Point A" a valve...

Suppose an ice cube is in a vessel and it is at a temperature slightly below 0 degrees Cesius. Suppose further that the inside of the vessel is a vacuum. If the temperature of the vessel is increased to slightly above zero Celsius and the vacuum is maintained would the state change in the ice...

From reading about the permeation of gasses through polymer seals, I am led to believe that given two identical sealed chambers, one containing a vacuum and the other pressurized perfectly dry nitrogen, water vapor would permeate through the seals and into the chambers at the same rate. This...

Hello, I am by far not very firmiliar with physics nor engineering. I had an idea a couple years ago involving the replacement of the propane in hot air balloons with hydrogen gas as the fuel to burned to provide the heat to lift the balloon. One thing I didn't realize back then was that...

Scenario A: An icicle on the eaves of Uncle Ivan’s dacha in far off Verkhoyansk vaporizes a number of water vapor molecules at an ambient temperature of -80°C. Over the succeeding months, one of these molecules makes its random way to the surface of a cloud droplet over Ouagadougou. Along the...

In psychrometrics it is outlined time and again that we cannot achieve a pure humidification process i.e, add only moisture to unsaturated air without a change in its Dry Bulb Temperature(DBT).While pondering over the idea I came up with a possible way of doing it (if it is correct at all) and...

As we all know that in atmospheric pressure (1 Bar) saturation temperature of water is 100 deg C. And the air contains mixture of dry air and water vapour. My doubt is here that the water needs 100 deg Celsius to change from liquid to vapour state then how can a normal room temperature air...

Is it simply the gaseous state of a liquid substance? For instance, water vapor, in this context, would be the gas state of water after having transitioned from a liquid state.

Both water vapor and wet steam contain both contain tiny droplets of water particles(correct me if I'm wrong).Does it mean both water vapor and wet steam are same and one ?

Homework Statement The partial pressure of water vapor in air at 200 is 10[mm] mercury. according to the table of partial pressures we have to cool the air to 11.40 in order to bring the air to saturation, that is100% relative humidity. this according to the book. But when we cool the pressure...

Homework Statement Two pounds of water vapor at 30 psia fill the 4ft^3 left chamber of a partitioned system. The right chamber has twice the volume of the left and is initially evacuated. Determine the pressure of the water after the partition has been removed and enough heat has been...

hi all My question is: In a pressurized (close to 1.1 atm; B.P. 109 degrees), closed system of water mixed (in a ratio of 1000 lts to 20lts) with Boron Nitrite (yes I am talking about cooling water system for automobiles) where the temp of the mixture does not exceed 96 degrees Celsius; will...

Hi all, Yet another noob question from me... I been thinking of Solarthermal desalination plant lately but I'm surprised that no plan seems to take into account the possibility of letting the vapor rise to a much higher level, thus creating a potential energy source. Is there something...

Homework Statement We insert into a copper container (weighing 1.5 Kg) 3 Kg of water vapour at 100 ºC. Inside the container there are 10 Kg of ice at -10ºC. Find the ΔT when the system reaches the equilibrium. Known data: the specific heats of water, copper and ice and the latent heat of...

Hi I need to know how i can separate the water vapor from biogas i know that there is separation of H2S and Co2 but what the procedure to remove water vapor from biogas ? thank you :)

Homework Statement How much water vapor (100 ° C) should be added to 120 g of ice (0 ° C) so that the final system has a final temperature of 35° C. Homework Equations Qvapor = lvapor * mvapor during condensation, where lvapor =2260 kJ/kg Q1 = cwater*mvapor*ΔT during cooling, and...

hello folks, let me apologize if this was addressed before, but every time I try to search for partial pressure of oxygen and water, I get problems unrelated to mine. I also searched Wikipedia and Google and found their explanations a bit too obtuse. But it's possible I'm just doing a bad job...

http://www.bbc.co.uk/news/science-environment-25849871 Herschel space telescope press release: http://sci.esa.int/herschel/53125-herschel-discovers-water-vapour-around-dwarf-planet-ceres/ Abstract of scholarly article published in Nature...

Hi - I'm a physics newbie so this is an elementary question, but I can't find the answer with a google search. Water evaporates at a wide range of temperatures, what is the latent heat in the water vapor (in calories or Joules), for example, at 30°C, 60°C? Assume standard atmospheric...

Homework Statement If a known amount, let's say 300 liters of water gas (water vapor) is flowing from an atmospheric (14.7 psi) source/chamber, into a chamber of reduced pressure of 10 psi, does the volume amount and/or moles change? Homework Equations So I believe I would multiply the...

How are the satellites that detect water vapor made? What goes into them that allow companies such as NOAA to create those water vapor images?

Homework Statement Doing a lab here, but were kind of stuck. This lab is meant to experiment the formula PV=nRT, and the set up is a canister of CO^2 with a fixed volume that has a pressure sensor connected to it reading in pascals. We heat up the CO^2 by placing the canister in a beaker of...

There is a simple method to separate the water vapor from the atmospheric air, however, in the form of gas and not of condensed water?

Superheated H20 at 400 kPa is slowly cooled in a sealed rigid vessel until the temperature is measured to be 115 centigrade, when condensation first occurs. What is the Initial Temperature? I know that the temperature and pressure at point two (saturated vapor) can be found in a standard...

I understand that some water vapor escapes into space but what's the amount say per year?

Hi.. I'm a pilot and I'm trying to get a better grasp on meteorology. I'm wondering how exactly water vapor is contained in air. I understand it's mostly governed by the temperature of the air but does the temperature of the water affect that? Why is it dependent on the temperature of the air...

Homework Statement A gas mixture of 0.13 mol NH3, 1.27 mol N2, and 0.025 mol H2O vapor is contained at a total pressure of 830 mm Hg and 323 K. Calculate the following: (a) Mole fraction of each component. (b) Partial pressure of each component in mm Hg. (c) Total volume of mixture in m3...

Can a solid, no matter how small, even a single cell, be evaporated with water vapor from a pool of water?

Homework Statement 1- Use the thermodynamic table to establish an equation giving the molar entropy of liquid water as a function of temperature. Do the same for water vapor. 2- Use these equations to calculate the entropy of vaporization and the enthalpy of vaporization. 3- From the...

Homework Statement Sealed container which is used to heat 200 kg water is initially at 25 degrees C. Since the container is sealed, the water remains in saturated state while its temperature and pressure increases. The remaining volume of the container is filled with water vapor at the same...

Homework Statement Compute the maximum amount of water vapor per unit volume that air can hold at the surface, where Ts = 288 K, and at a height of 10 km where T = 220 K. Express your answers in kg m-3. Homework Equations e_{s}=Ae^{\beta T} e=\rho _{v}R_{v}T The Attempt at a...

The following is something that puzzles me a bit, and I'd appreciate some insight in the matter. Thank You :) Given the following: A shallow pan with a smaller diameter beaker sitting in it's center Both the pan and the beaker contain distilled water The level of the water in the beaker...

Hi there, I am trying to calculate the precipitable water vapor, or column water vapor amount, from a given volume mixing ratio at a particular pressure. What is the procedure to do this? I understand you can convert volume mixing ratio to mass mixing ratio, by multiplying by the ratio of...

Homework Statement Find the mass of water vapor. this is the reaction: NaHCO3+HCl-->NaCl+CO2+H2O V=39.5 L P=18.65 mm Hg T=294 K n=30.5 mol H20 (g) pressure of room= 29.68 inHg=753.87mm Hg Homework Equations The Attempt at a Solution Would i have to use this equation...