The terms ‘vaporization’ and ‘evaporation’ are quite confusing and it might be very difficult for you to differentiate between the two. In both processes, there is a change in states of matter from liquid or solid to gaseous.
When water boils and gets converted into vapors, what is the process called? Is it called evaporation or is it called vaporization? When water from an ocean or a sea or a lake or a pond or any water body converts into gaseous form, is it vaporization or is it evaporation?
Vaporization vs Evaporation
The main difference between vaporization and evaporation is that vaporization is a broader term and it is the change of a solid or a liquid into a gaseous state while evaporation is the change of a liquid into its gaseous form. Also, vaporization occurs in the whole mass of the substance while evaporation occurs on the surface of the liquid.
Comparison Table Between Vaporization and Evaporation
| Parameters of Comparison | Vaporization | Evaporation |
| Definition | Vaporization is the phenomenon of change of a solid or a liquid into vapors at a fixed temperature and a fixed pressure. | Evaporation is the phenomenon of the change of a liquid into vapors at any temperature below its boiling point. |
| Speed | Vaporization is a fast and vigorous process. | Evaporation is a slow and silent process. |
| Temperature change | The temperature during vaporization remains constant. | The temperature during evaporation might change. Evaporation can occur at any temperature below the boiling point of the liquid. |
| Factors affecting | The process of vaporization doesn’t depend on external factors. | Evaporation depends on factors like surface area, temperature, humidity, and wind speed. |
| Nature | It is a bulk phenomenon that means the process of vaporization takes place over the entire mass of the liquid. | It is a surface phenomenon that means it occurs only on the surface of the liquid. |
What is Vaporization?
Vaporization is a fast and vigorous process in which a solid or a liquid is converted into its gaseous form at constant temperature and pressure. Unlike evaporation, vaporization is a bulk process in which the whole mass of the liquid changes into vapors.
Vaporization in a literal sense means the formation of vapors. People generally refer to boiling as vaporization but vaporization includes 3 terms:
- Boiling
When a liquid is heated to its boiling point, it converts into gas with the formation of bubbles, and this process is called boiling. At this point, the vapor pressure equals the surrounding pressure.
- Sublimation
It is the process of direct conversion of a solid into gas on heating without conversion into liquid.
- Evaporation
It is the process of conversion of liquid into a gas at any temperature below the boiling point of the liquid.
Examples of vaporization are:
- Boiling of water on a gas stove.
- Cooling of hot tea or coffee.
What is Evaporation?
Evaporation is a slow and gradual process. An example of evaporation is the conversion of the water from the seas, oceans, lakes, etc. into gas. When sun rays fall on the surface of these water bodies, the water molecules get excited and when they gain enough energy, they escape in the form of gas.
Evaporation is affected by the following factors:
- Temperature
The more the temperature the more is evaporation. Thus, the rate of evaporation is directly proportional to the temperature.
- Humidity
The rate of evaporation is inversely proportional to humidity. As you would have observed that on a humid day (when the surrounding is full of moisture), our clothes take a much longer time to dry up as compared to normal days. It is because the air is itself laden with moisture and due to this humidity, the rate of evaporation is slow.
- Wind speed
The rate of evaporation is directly proportional to wind speed. So on a windy day, evaporation would be more.
- Surface area
From a larger surface area, more water would be evaporated since the rate of evaporation is directly proportional to the surface area.
Examples of evaporation areas follows:
- Perspiration
Evaporation just like transpiration leaves a cooling effect. Our body perspires to maintain the body temperature by keeping it cool in hot temperatures.
- Drying of wet clothes.
Main Differences Between Vaporization and Evaporation
- Vaporization is the process of conversion of solid or liquid into gaseous form while evaporation is the change of a liquid into gaseous form.
- Bubbles are formed in the process of vaporization while in evaporation, bubbles aren’t formed.
- External factors do not affect the process of vaporization while evaporation is affected by external factors.
- Vaporization is a bulk phenomenon while evaporation is a surface phenomenon.
- Vaporization is a fast and violent process while evaporation is a slow process.
- Vaporization occurs at a constant temperature and pressure while evaporation can occur at any temperature.
Conclusion
To convert into its gaseous form, the liquid particles need sufficient energy to overcome their intermolecular forces of attraction and when it gets sufficient energy, it escapes into the surrounding area converting into gas. This process of conversion of liquid into a gas is either boiling or evaporation, both of which come under vaporization.
Vaporization is thus the conversion of liquid or solid into a gas at a constant temperature and pressure. It’s unaffected by external factors and there is the formation of bubbles during this process. Also, it is a bulk phenomenon.
Evaporation, on the other hand, is the conversion of liquid into a gas at any temperature below its boiling point. It is affected by several factors and there are no bubbles formed in the process. It is a surface phenomenon.
References
- https://www.sciencedirect.com/science/article/pii/S0378381209002180
- https://repository.rothamsted.ac.uk/item/8v5v7/evaporation-and-environment
- http://nora.nerc.ac.uk/id/eprint/5783/1/IH_056.pdf
- https://link.springer.com/article/10.1007/BF00566011