- Definition & Examples. Evaporation is the process of a substance in a liquid state changing to a gaseous state due to an increase in temperature and/or pressure. Evaporation is a fundamental part of the water cycle and is constantly occurring throughout nature.
How evaporation is useful?
Some of the most useful effects of evaporation:1. Water is in earthen pots because water seeps through the pores on to the outside from where it evaporates fast due to large surface area. The latent heat required for evaporation is taken from the water within the pot, which is therefore cooled.
When water is heated, it evaporates. The molecules move and vibrate so quickly that they escape into the atmosphere as molecules of water vapor. Evaporation is a very important part of the water cycle. Heat from the sun, or solar energy, powers the evaporation process.
When evaporation occurs then than the liquid (mostly water) absorbs all the heat from the surroundings and take it with it and we feel cool. evaporation causes cooling effect because the heat energy is abosorbed by surrounding particles.
The remaining particles in the liquid have a lower average kinetic energy than before, so the liquid cools down as evaporation happens. This is why sweating cools you down. The sweat absorbs energy from your skin so that it can continue to evaporate.
When liquid water meets dry air, it is not in equilibrium; water molecules evaporate off the surface until the amount of water in the air creates enough vapour pressure to achieve equilibrium. When water is heated to a temperature of 100C, the vapour pressure equals that of sea-level air pressure.
This is good for separating a soluble solid from a liquid (a soluble substance does dissolve, to form a solution). For example copper sulphate crystals can be separated from copper sulphate solution using evaporation. Remember that it is the water that evaporates away, not the solution.
Evaporation: Evaporation is when the sun heats up water in rivers or lakes or the ocean and turns it into vapor or steam. The water vapor or steam leaves the river, lake or ocean and goes into the air. Water vapor in the air gets cold and changes back into liquid, forming clouds.
Evaporation is a free surface process. Boiling is an entire bulk process that gets triggered from the solid interfaces and phase change occurs at the free surfaces. Boiling happens at a given temperature when the saturation vapour pressure of the liquid equals the atmospheric pressure.
The sun, which drives the water cycle, heats water in the oceans. Some of it evaporates as vapor into the air; a relatively smaller amount of moisture is added as ice and snow sublimate directly from the solid state into vapor.
Since the kinetic energy of a molecule is proportional to its temperature, evaporation proceeds more quickly at higher temperatures. As the faster-moving molecules escape, the remaining molecules have lower average kinetic energy, and the temperature of the liquid decreases.
Evaporation usually occurs on the surface. Evaporation may occur when the partial pressure of vapor of a substance is less than the equilibrium vapour pressure. Boiling is a phase transition from the liquid phase to gas phase that occurs at or above the boiling temperature.
An evaporator is a device in a process used to turn the liquid form of a chemical substance such as water into its gaseous-form/vapor. The liquid is evaporated, or vaporized, into a gas form of the targeted substance in that process.
The sun, which drives the water cycle, heats water in the oceans. Some of it evaporates as vapor into the air. Evaporation also occurs from freshwater lakes and rivers. On land, evapotranspiration, which is water transpired from plants and evaporated from the soil, contributes vapor to the air.
Many factors affect evaporation:
- Surface area of the liquid exposed to the atmosphere.
- Wind speed and.
Evaporation is one of the two forms of vaporization. It is the process whereby atoms or molecules in a liquid state (or solid state if the substance sublimes) gain sufficient energy to enter the gaseous state. It is the opposite process of condensation.
Evaporation is an essential part of the water cycle. The sun (solar energy) drives evaporation of water from oceans, lakes, moisture in the soil, and other sources of water. In hydrology, evaporation and transpiration (which involves evaporation within plant stomata) are collectively termed evapotranspiration.
If heat is added to water, it evaporates. In the hydrologic cycle, water from oceans, lakes, swamps, rivers, plants, and even you, can turn into water vapor. Water vapor condenses into millions of tiny droplets that form clouds. Clouds lose their water as rain or snow, which is called precipitation.
Heat can be transferred by infrared radiation. Unlike conduction and convection, which need particles, infrared radiation is a type of electromagnetic radiation that involves waves. Radiation can even work through the vacuum of space.
The surface area affects evaporation because if more area is exposed to air, allowing water molecules acquire more heat energy from the surroundings. Due to the increased heat energy (kinetic energy), there is more rapid movement of the water molecules which helps them to overcome the force of attraction and evaporate.
Condensation is the change of water from its gaseous form (water vapor) into liquid water. Condensation generally occurs in the atmosphere when warm air rises, cools and looses its capacity to hold water vapor. As a result, excess water vapor condenses to form cloud droplets.
Above 212°F at standard pressure, liquid water is unstable. It will evaporate very rapidly from the surface. If the temperature is held constant (which requires some heat input, since evaporation cools things) the liquid will all evaporate. If the temperature is much above 212°F, the water will boil.