Why substances can undergo sublimation and turn into gas?

[kfa]

Why is is that certain substances, (example: solid carbon dioxide) can undergo sublimation and turn into gas without undergoing liquid form when heated?

What is the general characteristics that enable certain substances to undergo sublimation?

Is it possible to have a substance that can undergo sublimation and melting process when heated?

 

[Claude Bile]

(You may be better served asking this in the chemistry forum.)

Sublimation can occur for just about any substance under the right conditions (for example, water can undergo sublimation when the pressure is less than that at the triple-point). In other words, I think you will find that the conditions (temperature and pressure) rather than the substance itself is more critical in determining whether sublimation occurs or not.

The next logical question is therefore "why do some substances more readily undergo sublimation at room temperature and pressure than others?". That is a question for the chemists.

Claude.

 

[sir-pinski]

Sublimation is the process in which a substance transitions directly from its solid state to its gas state without passing through the liquid state. This is because the substance's vapor pressure at its solid state is greater than its liquid state. Therefore, when heated, the molecules of the substance have enough energy to break free from the solid phase and become a gas.

Certain substances, such as solid carbon dioxide (dry ice), can undergo sublimation because of their unique molecular structure and intermolecular forces. These substances have weak intermolecular forces, meaning the bonds between their molecules are not as strong as other substances. This allows the molecules to easily break apart and become a gas without needing to go through the liquid state.

The general characteristics that enable certain substances to undergo sublimation include low melting points, low boiling points, and low intermolecular forces. These characteristics allow the molecules to easily break free from the solid phase and become a gas when heated.

It is possible for a substance to undergo both sublimation and melting processes when heated. This is because the conditions required for sublimation and melting are different. Sublimation occurs at a lower temperature and pressure compared to melting. So, a substance can undergo sublimation at a certain temperature and pressure, and then undergo melting at higher temperatures and pressures. This is seen in substances like iodine, which can undergo both sublimation and melting processes.