Questions tagged [evaporation]

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9
votes
1answer
181 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 ...
6
votes
5answers
759 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 ...
5
votes
1answer
695 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 ...
4
votes
3answers
102 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 ...
3
votes
1answer
77 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 (...
2
votes
1answer
73 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
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2answers
374 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 ...
1
vote
1answer
107 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
vote
1answer
81 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
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1answer
116 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
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1answer
44 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 ...
0
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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 ...
0
votes
3answers
437 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 $P^0\chi_{solvent}$. ...
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
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0answers
49 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 ...
0
votes
0answers
22 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 ...
-1
votes
2answers
57 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 ...
-2
votes
1answer
34 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 ...
-4
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0answers
25 views

Does evaporation break the bonds between hydrogen and oxygen? [closed]

After sublimation occurs in ice to create a gas, is the product hydrogen gas + oxygen gas? Or H2O in a gaseous state? Will the molecular bonds break?