Untangling the dilemma of Gas & Vapour
In physical chemistry, the term Vapour and Gas both are used. Students are often confused between both terms. Many think Vapour is the same as Gas(A big mistake). In this blog, I would like to clear the concept of Vapour & Gas for students who have been finding it difficult and are confused by the same.
While the differences between Vapour and Gas are few. But it’s very crucial to know them to make sure all confusion is avoided
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. Ex Petroleum Vapour, Camphor Vapour, Water Vapour, etc. Gases owing to the low intermolecular force of attraction remain in the gaseous phase at that temperature.
Difference between Vapour and Gas
Usually, a vapour phase consists of a phase with two different substances at room temperature, whereas a gas phase consists of a single substance at a defined thermodynamic range, at room temperature. Thus, this is defined as the key differences between Vapor and Gas. You can find the major differences in the table below.
Important points about Vapour
1. Vapour is a mixture of two or more different phases at room temperature, these phases are liquid and gaseous phases.
2. Vapour has a definite shape of the gaseous particles when observed under a microscope.
3. Vapour consists of random molecules and atoms moving randomly about. 4. They often have a more intermolecular force of attraction than gases
5. Vapour is not a state of matter, unlike gases.
6. Vapours of water are around us all the time at temperatures below the boiling point of water.
Important points about Gas
1. Gas usually contains a single thermodynamic state at room temperature.
2. Gas does not have a definite shape when it is observed under a microscope
3. Gas also consists of random molecules and atoms moving about randomly.
4. Gases are a state of matter.
5. Gases are usually formed above its critical temperature, but below critical pressure.
Happy Learning!
