Questions tagged [vapor-pressure]

This is the pressure exerted by a vapor in thermodynamic equilibrium with its condensed phases (solid or liquid) at a given temperature in a closed system. Apply this tag to questions involving clarification related to vapor pressure.

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Why don't minerals evaporate from seawater along with the water? [duplicate]

When water evaporates from the ocean, of course the minerals such as salt remain in the ocean-- that's why seawater is so saline. However, I'm very puzzled: why don't minerals evaporate along with the ...
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Does benzene vapor react with air in a closed barrel?

If we would have benzene in a closed barrel for quite a while at room temperature, some vapor would form fast due to its volatility, right? But let's say that when the barrel was closed, some air got ...
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What is the difference between volatility and evaporation?

I've been trying to find the difference between volatility and evaporation and I can see almost everywhere that the volatility is the tendency of a substance to vaporize. So Q1: what makes the ...
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Osmotic pressure of a solution of a protein?

A small protein molecule, code-named "sloth", has a MM of $\mathrm{1.50 x 10^4}$ g/mol. What is the osmotic pressure exerted at $\mathrm{24.0^oC}$ by 25.0 mL of an aqueous solution that contains $\...
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how to determine the volatility of an organic compound using the physical properties of organic molecules

How do you tell if a compound has a high volatility? Also can the boiling point of a compound be taken into consideration when determining if a compound has a high volatility?
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If some particles of liquid in a solution convert to vapour then why can't some liquid particles convert to solid?

I was reading about the vaporisation of liquid when I came across the following statement. The average energy of the particles in a liquid is governed by the temperature. The higher the ...
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Vapor pressure lowering

I have got this problem in my text book, Consider these three mercury manometers. One of them has 1 mL of water placed on top of the mercury, another has 1 mL of a 1 m urea solution placed ...
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349 views

Identifying T1 and T2 in the Claperyon equation

Is there a way to identify T1 and T2 in the two point form of the claperyon equation? I suspect that the greater temperature is T1 and the smaller temperature is T2.
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how to find pressure of a liquid when given volume (1 and 2) and one pressure?

A 5 mL sample of an unknown liquid is placed into a 250 mL flask that has had all of the air removed. The pressure measured in the flask is found to be 35.4kPa. In a seperate trial the student puts ...
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At the freezing point, why is the vapor pressure of the liquid phase equal to the vapor pressure of the solid phase?

At the freezing point of a substance, the solid phase is in dynamic equilibrium with the liquid phase. My textbook defines the freezing point of a substance as: "the temperature at which the vapor ...
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Why is Trouton's rule not valid for liquids with boiling points less than 150 K?

This is a question from the last year's semester examination. Why is Trouton's rule not valid for liquids with boiling points less than 150 K? I searched the internet but only found that the ...
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Is it correct to say that SOME iodine undergoes sublimation at 1 ATM

The triple point of Iodine occurs at 0.12 atm and at standard temperature it is a solid on the phase diagram. I understand that therefore, when heating iodine at 1 atm, it (at least some of it) will ...
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Determining the amount of water to create a given pressure in a sealed container

I have a sealed container with a volume of 1 liter. I want to go from an initial pressure of $P_{1}=1\ \mathrm{atm}$ and an initial temperature of $T_{1}=298\ \mathrm{K}$ to a final pressure of $P_{2}=...
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Why is Diiron nonacarbonyl so exceptional?

My textbook(NCERT) says: With exception of $\ce{Fe2(CO)9}$, all other metal carbonyls are soluble in hydrocarbon solvents. Weller, M.; Overton, T.; Rourke, J.; Armstrong, F. Inorganic Chemistry, ...
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Interpreting the phase diagram of a minimum boiling azeotrope

Exactly what does the line AB signify in the above phase diagram? Also, why is the curve divided at the azeotropic point?
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Relationship between surface area and vapor pressure

How is vapor pressure independent of the surface area and volume of a liquid, although rate of evaporation depends on surface area? Please someone help me I am totally confused.
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Steam Pumpkin Launcher

I am doing a pumpkin launcher project and my group is torn between using an air cannon, trebuchet, centrifugal arm, and a steam cannon. I want to take water fill the tank x % with water and heat it to ...
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Change in volume of two beakers on reaching equilibrium

Two beakers are placed side by side in a sealed container. The first beaker contains 100 ml of pure water. The other an equal volume of an aqueous solution of sugar. What should be the volume of the ...
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will mercury vaporize in boiling water in a flask?

Will mercury vaporize with the water vapours if boiled in a flask full of water? Also if we store mercury under water in the beaker will it still give vapours? If some mercury is bound to vaporize , ...
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vapour pressure above 2 separate beakers containing liquids which form ideal solution

Suppose we have A moles of liquid 1 in one beaker and B moles of liquid 2 in the other. Beakers are placed together in a biger closed container. Both have different vapour pressure when isloated. Now ...
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The effect of pressure on boiling point?

My textbook states the following: Qualitatively, I understand why the boiling point of a substance increases when the pressure is increased. However, I learned that if the pressure is increased when ...
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Vapour Pressure in Closed Containers [closed]

When the vapor pressure exerted by the gas equals that exerted by the liquid, do their densities equal?
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What is the formula for evaporation rate of water? [closed]

I did my own research, and according to The Engineering Toolbox,the formula for the evaporation rate of water is as follows: $g_\mathrm h = \Theta A (x_\mathrm s - x)$ $g_\mathrm h$ = amount of ...
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Could compressed refrigerant be stored feasibly in residential setting?

In Vapor-compression refrigeration, a refrigerant is compressed releasing heat (typically outside a building) and then decompressed in another location, absorbing heat. A residential air conditioner ...
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How many litres of water will be sufficient to generate 1600 psi when heated?

Here's my setup. I have a pressure vessel with x liters of water. I'll be heating the water at 320 C. I want to achieve at least 1600 psi of force inside the pressure vessel. So how do I calculate ...
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495 views

Why does Raoult's law work? [duplicate]

I am trying to look for the entropy explanation but I do not understand anything I can find. Please keep it simple but talk about it from a entropy point of view. Use water and a volatile solute as an ...
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681 views

Effect of an inert gas on steam vapor pressure at equilibrium

Suppose we have a closed container with mobile walls, so it will change its volume in order to equal the external pressure(constant) to the internal pressure. This container has inside it a liquid ...
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Vapour Pressure and Equilibrium

I found this questions on a YouTube lesson and I'm confused with the answers they have given: "A liquid in its equilibrium with its vapour is in a sealed container at a fixed temperature. The ...
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Heating of mixture of gases with one gas barely above its boiling point

What happens when mixture of two gases is heated in a closed container? If one gas expands faster than the other and increases pressure of the container enough so that the boiling point of the other ...
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Vapor pressure of immiscible liquids

I have read that vapour pressure of a mixture of two immiscible liquids is $$P=P^0_A + P^0_B$$ where A and B are immiscible liquids. If they are immiscible, they would form separate layers. Thus ...
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Control the pressure of Hydrogen in a small container without the use of a pressure regulator

I had recently asked this question, and due to the comments and general consensus of safety concerns, I decided to re-ask the question, attacking the problem from another angle. The Problem I need ...
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654 views

Vapor-pressure or Vapor-concentration

To summarize from my textbook: rate of evaporation: proportional to surface area but essentially independent from pressure (of surrounding gas) rate of condensation proportional to both surface ...
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What is the lowest temperature tungsten starts sublimating at?

What is the lowest temperature tungsten starts sublimating at? I've tried to search in Google but without any luck. For example, $\ce{WO3}$ starts sublimating roughly at $\pu{550 °C}$, according to ...
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How is volatility useful in the production of acids?

Sulfuric acid because of its low volatility can be used to manufacture more volatile acids from their corresponding salts. How does volatility affect the production of acids? Isn't it that sulfuric ...
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Calculating the mass of water removed by air conditioning condensation

I cannot figure out how to calculate the mass. The question is: "Suppose the percent relative humidity is $\mathrm{80.0\%}$ at $\mathrm{91.4\ ^\circ F}$ ($\mathrm{33.0\ ^\circ C}$) in a house ...
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186 views

Why don't the solute molecules in a volatile solvent also escape to contribute to vapor pressure?

I'm currently studying relative lowering of vapor pressure with the addition of a solid non volatile solute. The book explains it with the notion that some of the non volatile solute also appears at ...
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Colligative properties

I have some problems with these properties. 1) Lowering vapor pressure and boiling point. It happens because the solute molecules take space in the surface of the liquid so a lower number of the ...
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Vapor Pressure - Sealed Vessel

I have read that vapor pressure is only affected by temperature, but all of the examples have been in a sealed vessel. I have also read that pressure does not affect vapor pressure. I am looking for ...
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Boiling point and vapor pressure

Does a liquid having higher vapor pressure have a lower boiling point? I think so because I read in wikipedia that, "A substance with a high vapor pressure at normal temperatures is often referred to ...
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When water boils at its boiling point how do we call it as an equilibrium?

On boiling, water becomes a vapor, liquid volume decreases and vapour volume increases. Since volumes are not constant, how do we call it as equilibrium?
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Raoult's Law and Mole Fraction

Raoult's Law states that the partial vapor pressure of each component of an ideal mixture of liquids is equal to the vapor pressure of the pure component multiplied by its mole fraction in the mixture....
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Rocket propellants: accuracy of vapor pressure estimation techniques

I would like to determine the vapore pressures of a couple of substances (rocket propellants) over a significant temperature range within a ~10% error margin. For a first test, I tried to ...
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What is the connection between vapor pressure and intermolecular force explanations of boiling?

I've had boiling explained to me in two ways, and I'm having trouble understanding how they connect. The first way is that a liquid is held together by the intermolecular forces, and boiling involves ...
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Is menthol an especially volatile molecule?

I have been studying a bit about odors and plant essential oils. Several sources claim that the fragrant terpenes found in these oils, such as menthol, eugenol, limonene, linalool, etc. are volatile ...
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Why does melting point depend on external pressure?

The melting point of a substance is the temperature at which the solid form's vapor pressure equals the liquid form's vapor pressure. I read that the vapor pressure of something depends ONLY on the ...
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What is the mass fraction of C2HCl3 in the liquid phase?

Vapour-liquid equilibrium of a two-component ideal solution of trichloroethene (C2HCl3) and trichloromethane (CHCl3) is established at 25 °C. The mole fraction of CHCl3 in the vapour phase is 1. What ...
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Mass of sugar that was added to the water (Raoult's law)

Water has a vapour pressure of $15.5~\mathrm{mmHg}$ at $25~\mathrm{^\circ C}$. An unknown amount of the non-volatile sugar glucose ($\ce{C6H12O6}$) is added to $1.31~\mathrm{kg}$ of water and the ...
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Calculate the mole fraction of component B in this solution? (partial pressures)

The vapour pressure of a pure liquid solvent A is $\pu{0.80atm}$. When a non volatile substance B is dissolved in the solvent, its vapour pressure drops to $\pu{0.60atm}$. Calculate the mole fraction ...
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Does storing a hygroscopic reagent in a bottle makes it prone to absorb humidity from the air trapped inside?

I've got a full bottle of 99,5% acetone, which I'd really like to keep it as dry as possible, though without using molecular sieves or other dessicants. Once I open the bottle for the first time, use ...
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Is every substance in equilibrium with its vapours?

In one of my previous questions, I got an answer from user Jan: The smell of a compound as we perceive it usually depends on which receptors in the nose will bind the molecule (or not). These ...