CBSE Online Class 9 Science – Evaporation Vs Vaporization Evaporation and vaporization are two commonly occurring processes in our nature. These two processes are the primary reasons behind rainfall. In fact, evaporation is a type of vaporization that occurs in our surroundings. Although these two words seem to have similar meanings, many differences still exist. Therefore, we will understand what the two terms mean and how they differ from one another. Before we proceed, we encourage you to have a basic understanding of the states of matter. To get an understanding, check out our blog.
What is vaporization? Have you ever seen a boiling pot of water left for far too long on the stove? I definitely have every time I make Maggi for myself. And every time, half the water just magically vanishes! So this magical process is called vaporization – It is the process by which intense heat is used to transfer a substance from a solid or liquid state to a gaseous state. It should be noted that these changes occur from one state of matter to another without any change in the chemical composition.
Vaporization can be of three types – Boiling – During the boiling process, the transition from the liquid phase to the gaseous phase occurs at or above the boiling temperature. This process leads to the formation of vapour as bubbles of high-temperature water below the surface of the liquid. Our initial example of water on the stove involves the process of boiling. Sublimation – The sublimation process of vaporization directly transitions a solid to a gas without passing through the liquid phase. Evaporation – Similar to boiling, evaporation involves the transition of a solid or liquid to gas. However, this transition occurs at temperatures lower than the boiling temperature. Now let’s learn more about this!
What is the evaporation process? As stated above, the evaporation process is a type of vaporization wherein a solid or liquid transforms into gas and this process takes place below the boiling
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point at a given pressure. Evaporation is a slow process that requires massive energy. A very prominent example of the evaporation process is our planet’s water cycle. The intense energy of the Sun provides heat to the planet’s various water bodies, such as the oceans, seas, and rivers. Further, water from other sources, such as moisture in soil and plants, also get heat from the Sun. As the Sun provides energy to such water sources, liquid molecules of water evaporate to form clouds. These clouds release water back to Earth in the form of rain. This example tells us that evaporation is the most common type of vaporization in nature as it does not require liquids to attain their boiling points.
Factors affecting Evaporation Evaporation can get affected by a number of factors as listed below – Temperature: An increase in temperature leads to an increase in the rate of evaporation. Surface area: An increase in the surface area of the substance leads to an increase in the rate of evaporation. Humidity: The amount of water vapour present in the air is called humidity. As humidity increases, the rate of evaporation decreases. Wind speed: An increase in wind speed leads to an increase in the rate of evaporation.
What is the difference between evaporation and vaporization? Although these terms get used interchangeably quite often because of their similarities, evaporation, and vaporization in fact differ largely on a molecular level. VAPORIZATION
EVAPORATION
DEFINITION
It is defined as the transition phase of a compound It is the process that most often occurs at or element at boiling temperature. temperatures below the boiling point.
TRANSITION STATE
OF It changes the state of matter from solid or liquid to a It directly converts the liquid state of matter into gaseous state. gas. It is a very slow process that requires more energy.
SPEED OF PROCESS
This is usually much faster and requires less energy.
AFFECTED AREA
In the process of vaporization, the entire substance During the evaporation process, only the topturns to gas. level water becomes gaseous.
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MOVEMENT MOLECULES
OF
Molecules can form on the surface of the liquid.
Molecules only evaporate from the surface of the liquid.
There is very little difference between vaporization and evaporation once liquids or solids turn into a gaseous form as condensation of gas as gas from both, evaporation and vaporization can turn into liquid as gas gets cooled. However, a fun thing to notice is that the transition between the states of matter from one to another occurs without any change in the chemical composition of the substance. Therefore, these changes are only considered as physical changes and not chemical changes. To get an understanding of physical and chemical changes, check out our blog.
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