Questions tagged [evaporation]
The evaporation tag has no usage guidance.
18
questions
0
votes
1answer
42 views
Boiling of ammonia water [closed]
L̶e̶t̶'̶s̶ ̶m̶a̶k̶e̶ ̶i̶t̶ ̶s̶i̶m̶p̶l̶e̶.̶ ̶I̶ ̶h̶a̶v̶e̶ ̶a̶ ̶p̶o̶o̶l̶ ̶o̶f̶ ̶a̶m̶m̶o̶n̶i̶a̶ ̶w̶a̶t̶e̶r̶,̶ ̶a̶n̶d̶ ̶w̶h̶e̶n̶ ̶I̶ ̶h̶e̶a̶t̶ ̶t̶h̶e̶ ̶a̶m̶m̶o̶n̶i̶a̶ ̶w̶a̶t̶e̶r̶,̶ ̶a̶m̶m̶o̶n̶i̶a̶ ...
2
votes
1answer
71 views
Some salts lower the vapour pressure of water - do any raise it?
Plain old NaCl salt can slightly lower the vapour pressure of water for a given temperature. Other salts such as CaCl₂ lower the vapour pressure to a larger degree.
Do any salts, or compounds of any ...
1
vote
1answer
106 views
In an open system, can water vapor escape into the atmosphere before reaching the boiling point? [duplicate]
In a closed system, water vapor would have nowhere to go and atmospheric pressure would not be a factor. It would reach dynamic equilibrium with only water vapor.
But in an open system, I think that ...
-1
votes
2answers
53 views
Why vapor pressure is unaffected by change in atmospheric pressure [duplicate]
I am a high school student and I am very confused in a topic about "vapor pressure of liquid". Why doesn't a change in atmospheric pressure affect vapor pressure? I think intuitively that ...
9
votes
1answer
178 views
Do azeotropic mixtures evaporate proportionally?
Do azeotropes evaporate, without boiling, in proportionate amounts, or does this property describe their behaviour only at boiling point?
Concretely, if 91% isopropyl alcohol/water (by volume, i.e. an ...
3
votes
1answer
71 views
Relative humidity and vapor-pressure in equilibrium
I have quite an unclear understanding of relative humidity. I am writing my understanding on the topic and please correct me wherever I'm wrong:
What I understood:
Let's say $\ce{H2O}$ has a (...
4
votes
3answers
100 views
If all molecules have basically the same KE at a given temperature, why do lighter isotopes evaporate more readily?
One of the proxies used for paleoclimate is the ratio of oxygen-18 to oxygen-16 in ice cores and in sedimentary rocks. The idea is that water molecules with oxygen-18 generally evaporate less readily ...
0
votes
0answers
47 views
Advice for a good solvent for fragrance
Hi any suggestions for a solvent for aroma oils, that has low evaporation and high diffusivity (low molecular weight and hence spreads well in the air). The solvent should also be soluble in water and ...
6
votes
5answers
710 views
Is the average kinetic energy of evaporating water molecules (at room temperature) equivalent to the average kinetic energy of boiling water?
Purpose:
On new year's eve, after a splendid red and an assortment of sumptuous repasts, I made a bold remark which, on further consideration, may turn out to be incorrect. Unless! Unless I can ...
1
vote
1answer
76 views
Definition of enthalpy of vaporization
The amount of heat required to vapourize one mole of a liquid at
constant temperature and under standard pressure (1 bar) is called its
standard enthalpy of vapourization.
The enthalpy of vaporization ...
1
vote
1answer
98 views
Comparison of evaporation rate of liquids
Evaporation: Evaporation
is a type of vaporization that occurs on the surface of a liquid as it
changes into the gas phase. When a molecule near the surface absorbs
enough energy to overcome the ...
0
votes
1answer
56 views
Dispersal of pyrethroid insecticide by vaporization - role of petroleum distillate in distribution in air
I live in Indonesia where there are many mosquitoes and products sold for their control.
One such product is this one:
The product contains 22ml of liquid, the contents of which likely vary slightly ...
0
votes
0answers
21 views
Isolating additives in alcohol products
Given an alcohol-water solution (Liquor products) that may have additives and/or may have been aged in wood, I'd like to boil off the alcohol and the water to leave behind the various additives in a ...
-2
votes
1answer
33 views
does NH4OH lose concentration when it is open? [closed]
I get a lot of variation on NH4OH titration and I am curious if anyone knows if NH4OH at concentration greater than 20% will evaporate the NH3 and decrease in concentration if it is open and at room ...
1
vote
2answers
368 views
How to make acetic acid more volatile so that it can be removed by vigorous aeration of an acetic acid-water mixture? [closed]
I want to remove acetic acid from a mixture of acetic acid and water by aeration. The concentration of acetic acid is 200 ppm (mg/L). The pH of the water is more than 5. I want to reduce the acetic ...
0
votes
3answers
418 views
Why does Vapor Pressure decrease on addition of solute? [duplicate]
Consider a vessel with a volatile liquid in it. Let's say it has a vapor pressure $P^0$ when it is pure.
Now a non-volatile solute is added to it. Its vapor pressure decreases as $P^0\chi_{solvent}$.
...
5
votes
1answer
689 views
Detailed kinetic explanation for vapor pressure reduction by dissolved solute?
The following problem was asked in JEE Mains 2020 (Sept 2, Shift 1),
An open beaker of water in equilibrium with water vapor is in a sealed container. When a few grams of glucose are added to the ...
0
votes
1answer
472 views
Mass change during phase transition
When you fill up a balloon about a quarter way with liquefied butane fuel and let it sit at room temperature it will turn into gas. But why does the gas weigh the same as the liquified butane?
The ...
