Full Answer
What is a vapor in chemistry?
In physics, a vapor (American English) or vapour (British English) is a substance in the gas phase at a temperature lower than its critical temperature, which means that the vapor can be condensed to a liquid by increasing the pressure on it without reducing the temperature.
What is vaporization?
What is Vaporization? Vaporization can be defined as the process in which liquid state changes into the vapour state. As a result of an increase in temperature, the kinetic energy of the molecules increases. Due to the increases in kinetic energy, the force of attraction between the molecules reduces.
What does water vapor mean in a sentence?
Definition of water vapor : water in a vaporous form especially when below boiling temperature and diffused (as in the atmosphere) Examples of water vapor in a Sentence Recent Examples on the Web Clouds form when water vapor sticks to tiny particles floating in the air.
What is water vapor pressure in chemistry?
Water vapor is water in the gaseous state and is invisible to the human eye. Water will turn into vapor, or evaporate, in order to reach equilibrium. Equilibrium is measured using partial pressure, the pressure from water vapor molecules in the air. Once water has reached equilibrium, the air has reached saturation vapor pressure.
What is a vapor in science?
Vapor describes the gas form of a substance when it exists in equilibrium with its liquid form, for example, when the temperature is low enough such that the substance can exist in gaseous or liquid form.
What is vapor and example?
The most common example of a vapor is water vapor (gas phase water) at room temperature and one atmosphere of pressure. Do not confuse a vapor with a dust, a fine suspension of solid particles or a mist, a fine suspension of liquid droplets. A good synonym (alternate word) for vapor is gas.
What is vapour in short answer?
noun. a visible exhalation, as fog, mist, steam, smoke, or noxious gas, diffused through or suspended in the air: the vapors rising from the bogs. Physics. a gas at a temperature below its critical temperature.
What is the process of vapor?
vaporization, conversion of a substance from the liquid or solid phase into the gaseous (vapour) phase. If conditions allow the formation of vapour bubbles within a liquid, the vaporization process is called boiling. Direct conversion from solid to vapour is called sublimation.
Is vapor a gas or liquid?
Vapour is simply defined as the phase of a gas at a temperature where the same substance can exist in both liquid and solid states.
Is water a vapor?
Water vapor, water vapour or aqueous vapor is the gaseous phase of water. It is one state of water within the hydrosphere. Water vapor can be produced from the evaporation or boiling of liquid water or from the sublimation of ice....Water vapor.Water vapor (H2O)Liquid stateWaterSolid stateIcePropertiesMolecular formulaH2O7 more rows
Why is water called a vapor?
Water vapour is water in gaseous instead of liquid form. It can be formed either through a process of evaporation or sublimation. Unlike clouds, fog, or mist which are simply suspended particles of liquid water in the air, water vapour itself cannot be seen because it is in gaseous form.
What is vapour in a sentence?
vapour noun (GAS) gas or extremely small drops of liquid that result from the heating of a liquid or solid: The hollow glass tank contains hot mercury vapour. Poisonous vapours burst out of the factory during the accident.
What is water vapor called?
(Also called aqueous vapor, moisture.) Water substance in vapor form; one of the most important of all constituents of the atmosphere.
What are types of vapor?
The two types of vaporization are evaporation and boiling. Evaporation refers to the surface of a body of liquid turning into gas, such as a drop of water on the concrete turning into a gas on a hot day.
What is vapor and steam?
“Vapor” is a group term for any substance (solid or liquid) that undergoes a gaseous state while “steam” is a specific term that denotes liquid in a gaseous state). In terms of hierarchy, “gas” is the broadest category followed by “vapor” as one of its types and, in return, followed by steam as a type of vapor.
Is steam a gas or vapor?
steam, odourless, invisible gas consisting of vaporized water. It is usually interspersed with minute droplets of water, which gives it a white, cloudy appearance.
What is boiling?
Boiling is the rapid vaporization of a liquid, which occurs when a liquid is heated to its boiling point,A liquid boils at a temperature at which i...
What is vaporization?
Vaporization can be defined as the process in which liquid state changes into the vapour state. As a result of an increase in temperature, the kine...
What is the main difference between boiling and vapourization?
Boiling is the process in which the liquid phase changes to gaseous phase at a constant temperature.Boiling means rapid vaporization of any liquid....
What is a vapor?
In physics, a vapor ( American English) or vapour ( British English and Canadian English; see spelling differences) is a substance in the gas phase at a temperature lower than its critical temperature, which means that the vapor can be condensed to a liquid by increasing ...
What is vapor in chemistry?
Vapor is responsible for the familiar processes of cloud formation and condensation. It is commonly employed to carry out the physical processes of distillation and headspace extraction from a liquid sample prior to gas chromatography . The constituent molecules of a vapor possess vibrational, rotational, and translational motion.
What is the name of the chemical that vaporizes at different temperatures?
Perfumes contain chemicals that vaporize at different temperatures and at different rate in scent accords, known as notes. Atmospheric water vapor is found near the earth's surface, and may condense into small liquid droplets and form meteorological phenomena, such as fog, mist, and haar. Mercury-vapor lamps and sodium vapor lamps produce light ...
What is the difference between a vapor and an aerosol?
A vapor is different from an aerosol. An aerosol is a suspension of tiny particles of liquid, solid, or both within a gas. For example, water has a critical temperature of 647 K (374 °C; 705 °F), which is the highest temperature at which liquid water can exist.
What is the equilibrium pressure of a liquid?
The vapor pressure is the equilibrium pressure from a liquid or a solid at a specific temperature. The equilibrium vapor pressure of a liquid or solid is not affected by the amount of contact with the liquid or solid interface. The normal boiling point of a liquid is the temperature at which the vapor pressure is equal to normal atmospheric ...
What happens when the vapor pressure exceeds the equilibrium value?
If the vapor pressure exceeds the equilibrium value, it becomes supersaturated and condenses on any available nucleation sites e. g. particles of dust. This principle is used in cloud chambers, where particles of radiation are visualized because they nucleate formation of water droplets.
What is the state of equilibrium of a gas?
If the vapor is in contact with a liquid or solid phase, the two phases will be in a state of equilibrium. The term gas refers to a compressible fluid phase. Fixed gases are gases for which no liquid or solid can form at the temperature of the gas, such as air at typical ambient temperatures. A liquid or solid does not have to boil ...
What is vapor in science?
Definition of vapor. (Entry 1 of 2) 1 : diffused matter (such as smoke or fog) suspended floating in the air and impairing its transparency. 2 a : a substance in the gaseous state as distinguished from the liquid or solid state.
What is vapor in medical terms?
Medical Definition of vapor. 1 a : a substance in the gaseous state as distinguished from the liquid or solid state. b : a substance (as alcohol or benzoin) vaporized for industrial, therapeutic, or military uses. 2 vapors or chiefly British vapours plural.
What is vapor for kids?
Kids Definition of vapor. 1 : fine bits (as of fog or smoke) floating in the air and clouding it. 2 : a substance in the form of a gas water vapor.
What is the process of ice cap?
At the top of the formation, where the ambient air temperature dropped below freezing, the vapor froze to create a smooth white surface, like a meringue— a process called ice-capping.
Why is water vapor invisible?
Water vapor is invisible, but as it rises and the temperature decreases, some of the molecules condense into liquid water. This, water's constant desire for equilibrium, is what allows us to see steam rising from the kettle and clouds forming in the sky. To unlock this lesson you must be a Study.com Member.
Which factors are responsible for the vaporization of water?
False, because the correct answer is: Water vapor is dependent on three factors, namely pressure, relative humidity, and temperature.
How much pressure does water vapor have to be to evaporate?
This means that the water will evaporate until the partial pressure of water vapor equals 3.18 kPa in the air. The water vapor will continue to float in the air until it reaches a lower temperature where the pressure does not need to be as high, and it will condense back into water. If this happens in the sky, we'll see clouds form. Eventually, enough water will collect and will fall as rain or snow. And the cycle continues.
Why does water evaporate at sea level?
But really this is only the boiling point at sea level pressure. As pressure decreases, we need lower and lower temperatures in order to evaporate water. If the pressure is low enough, we could even get water vapor directly from ice! Water will also evaporate in order to balance out dry air.
What happens when water vapor reaches a lower temperature?
The water vapor will continue to float in the air until it reaches a lower temperature where the pressure does not need to be as high, and it will condense back into water. If this happens in the sky, we'll see clouds form. Eventually, enough water will collect and will fall as rain or snow. And the cycle continues.
How are clouds formed?
Clouds are formed when water vapor floats into the sky and then condenses back into water. Water vapor still has the same chemical formula as typical water - H 2 O - but the water molecules in vapor interact less with one another and are not as structured as they are in water and ice.
Where does air pressure come from?
The pressure caused by air comes from a combination of all the particles in the air. When looking at the pressure from only one type of particle, water vapor in this case, its pressure is measured using partial pressure.
What is Vaporization?
Vaporization can be defined as the process in which liquid state changes into the vapour state. As a result of an increase in temperature, the kinetic energy of the molecules increases. Due to the increases in kinetic energy, the force of attraction between the molecules reduces. As a result, they escape into the surrounding in the form of vapours. This process involves the consumption of heat energy.
What are the two types of vaporization?
Types of Vaporization. Vaporization can be divided into two types. Evaporation. Boiling. Evaporation is different from boiling on the basis that evaporation is a surface phenomenon, unlike boiling which is a bulk phenomenon.
What happens to the rate of vaporization with the increase in surface area?
Surface area: With the increase in surface area, the rate of vaporization also increases as more number of particles is exposed to the change in temperature. Pressure: Pressure is inversely propositional to evaporation.
Why is water stored in earthen pots?
Water is stored in earthen pots especially in summers to keep the water cool. Earthen pots are made up of clay particles and have pores in them. When water is poured into the pot, it gets evaporated from the pores by absorbing heat from the remaining water in the pot.
Does temperature affect vaporization?
Temperature: Vaporization is directly proportional to temperature. As the temperature rises the kinetic energy of the molecules also increases. As a result, the force of attraction reduces. Hence, with an increase in temperature the rate of evaporation increases.
absolute humidity
vapour concentration or density in the air. If mv is the mass of vapour in a volume of air, then absolute humidity, or dv, is simply dv = mv / V, in which V is the volume and dv is expressed
crystal growth
Crystals can be grown from a vapour when the molecules of the gas attach themselves to a surface and move into the crystal arrangement. Several important conditions must be met for this to occur. At constant temperature and equilibrium conditions, the average number…
What is the pressure of a vapour?
Full Article. Vapour pressure, pressure exerted by a vapour when the vapour is in equilibrium with the liquid or solid form, or both, of the same substance— i.e., when conditions are such that the substance can exist in both or in all three phases. Vapour pressure is a measure of the tendency of a material to change into ...
What is the temperature at which the pressure of a liquid becomes equal to the pressure exerted by the surroundings?
The temperature at which the vapour pressure at the surface of a liquid becomes equal to the pressure exerted by the surroundings is called the boiling point of the liquid.
What is the unit of measurement used in characterizing the water vapor permeance of materials?
The unit of measurement typically used in characterizing the water vapor permeance of materials is the “perm.” It is further proposed here that there should be several classes of vapor retarders (this is nothing new – it is an extension and modification of the Canadian General Standards Board approach that specifies Type I and Type II vapor retarders – the numbers here are a little different however):
Where does water vapor move?
In general water vapor moves from the warm side of building assemblies to the cold side of building assemblies. This is simple to understand, except we have trouble deciding what side of a wall is the cold or warm side. Logically, this means we need different strategies for different climates.
Why is it so difficult to keep water vapor out?
No chance. It gets complicated because sometimes the best strategies to keep water vapor out also trap water vapor in. This can be a real problem if the assemblies start out wet because of rain or the use of wet materials. It gets even more complicated because of climate.
Why is there confusion about vapor barriers?
Confusion on the issue of vapor barriers and air barriers is common. The confusion arises because air often holds a great deal of moisture in the vapor form. When this air moves from location to location due to an air pressure difference, the vapor moves with it. This is a type of migration of water vapor.
Why are vapor barriers bad?
Incorrect use of vapor barriers is leading to an increase in moisture related problems. Vapor barriers were originally intended to prevent assemblies from getting wet. However, they often prevent assemblies from drying. Vapor barriers installed on the interior of assemblies prevent assemblies from drying inward. This can be a problem in any air-conditioned enclosure. This can be a problem in any below grade space. This can be a problem when there is also a vapor barrier on the exterior. This can be a problem where brick is installed over building paper and vapor permeable sheathing.
What is vapor barrier?
Vapor barriers installed on the interior of assemblies prevent assemblies from drying inward. This can be a problem in any air-conditioned enclosure. This can be a problem in any below grade space. This can be a problem when there is also a vapor barrier on the exterior.
What is the principle of control of water in the liquid form?
The fundamental principle of control of water in the liquid form is to drain it out if it gets in – and let us make it perfectly clear – it will get in if you build where it rains or if you put your building in the ground where there is water in the ground. This is easy to understand, logical, with a long historical basis.
What is vapor in science?from dictionary.com
Definition of vapor. (Entry 1 of 2) 1 : diffused matter (such as smoke or fog) suspended floating in the air and impairing its transparency. 2 a : a substance in the gaseous state as distinguished from the liquid or solid state.
Where is water vapor found?from en.wikipedia.org
Its signature has been detected in the atmospheres of the Sun, occurring in sunspots. The presence of water vapor has been detected in the atmospheres of all seven extraterrestrial planets in the solar system, the Earth's Moon, and the moons of other planets, although typically in only trace amounts.
Why does water vapor freeze?from wiki.kidzsearch.com
In the cold, breathing out causes the water vapor in the breath to freeze. Water vapor weighs less than air, thus slightly reduces the lift produced by an aircraft wing. Water vapour is transparent. The small droplets that look white like mist are actually liquid. Water vapour is a big cause of the greenhouse effect.
Why is water vapor invisible?from wiki.kidzsearch.com
Water vapor is invisible, but as it rises and the temperature decreases, some of the molecules condense into liquid water. This, water's constant desire for equilibrium, is what allows us to see steam rising from the kettle and clouds forming in the sky. To unlock this lesson you must be a Study.com Member.
Why does water evaporate?from study.com
Water will evaporate to try to ensure that enough water vapor is present in the air in order to reach a point of equilibrium. Equilibrium refers to a specific level of water in the gas phase versus the liquid phase needed to create an ideal partial pressure. This ideal partial pressure changes based on the temperature of the water.
How does water vapor affect the permittivity of the air?from en.wikipedia.org
The amount of water vapor directly controls the permittivity of the air. During times of low humidity, static discharge is quick and easy. During times of higher humidity, fewer static discharges occur. Permittivity and capacitance work hand in hand to produce the megawatt outputs of lightning.
How does water vapor transfer energy?from en.wikipedia.org
Whenever a water molecule leaves a surface and diffuses into a surrounding gas, it is said to have evaporated. Each individual water molecule which transitions between a more associated (liquid) and a less associated (vapor/gas) state does so through the absorption or release of kinetic energy. The aggregate measurement of this kinetic energy transfer is defined as thermal energy and occurs only when there is differential in the temperature of the water molecules. Liquid water that becomes water vapor takes a parcel of heat with it, in a process called evaporative cooling. The amount of water vapor in the air determines how frequently molecules will return to the surface. When a net evaporation occurs, the body of water will undergo a net cooling directly related to the loss of water.
How to prevent chemical vapors?
Passive vapor mitigation involves barriers installed in existing buildings or pre-construction to prevent the entry of chemical vapors. Passive vapor barriers are installed in a variety of structures including homes, businesses, or other industrial buildings and are generally a cost-effective approach, making passive vapor barriers the most common and appealing method for vapor mitigation. One approach available for existing structures is to seal or fill the cracks in a building’s floor slab or around pipes and utility lines in walls. Retro-Coat™ is an example of a vapor barrier coating system that protects existing structures and can be customizable to fit the unique needs of the structure. Another method of passive mitigation is installing a venting layer in a basement which pushes harmful vapors toward the sides of the building and then outdoors. A third vapor barrier option involves installing a barrier made up of strong plastic-like sheets placed beneath a building’s foundation or in crawl spaces. At Land Science, Geo-Seal® is a safe and proven vapor barrier system comprised of three intensive layers designed and installed in newly constructed buildings. Scientifically tested to provide the highest level of protection from vapor intrusion, Geo-Seal is the trusted source for many environmental professionals and developers across the US and Canada.
What is vapor mitigation?
Vapor mitigation is a segment of the environmental industry that is maturing rapidly. There are many new technologies emerging to prevent vapor intrusion which safely and effectively address a variety of structures. Vapor mitigation methods are classified as either passive or active. Passive vapor mitigation involves barriers installed in existing ...
What is positive pressure?
When positive pressure is introduced inside the building, it prevents chemical vapor from entering the building. This method tends to produce a high energy cost and is considered to be less-effective compared to SSD. Additionally, there are solutions developed using both passive and active methods. For example, a passive system can be designed ...
Overview
In physics, a vapor (American English) or vapour (British English and Canadian English; see spelling differences) is a substance in the gas phase at a temperature lower than its critical temperature, which means that the vapor can be condensed to a liquid by increasing the pressure on it without reducing the temperature. A vapor is different from an aerosol. An aerosol is a suspension of tiny particles …
Properties
Vapor refers to a gas phase at a temperature where the same substance can also exist in the liquid or solid state, below the critical temperature of the substance. (For example, water has a critical temperature of 374 °C (647 K), which is the highest temperature at which liquid water can exist.) If the vapor is in contact with a liquid or solid phase, the two phases will be in a state of equili…
Vapor pressure
The vapor pressure is the equilibrium pressure from a liquid or a solid at a specific temperature. The equilibrium vapor pressure of a liquid or solid is not affected by the amount of contact with the liquid or solid interface.
The normal boiling point of a liquid is the temperature at which the vapor pressure is equal to normal atmospheric pressure.
Examples
• Perfumes contain chemicals that vaporize at different temperatures and at different rate in scent accords, known as notes.
• Atmospheric water vapor is found near the earth's surface, and may condense into small liquid droplets and form meteorological phenomena, such as fog, mist, and haar.
Measuring vapor
Since it is in the gas phase, the amount of vapor present is quantified by the partial pressure of the gas. Also, vapors obey the barometric formula in a gravitational field, just as conventional atmospheric gases do.
See also
• Dilution (equation)
• Evaporation – Type of vaporization of a liquid that occurs from its surface; surface phenomenon
• Henry's law – Gas law regarding proportionality of dissolved gas
• Contrail, also known as Vapor trail – Long, thin artificial clouds that sometimes form behind aircraft