Question

Explain the process of condensation and sublimation with examples.

Answer 1

There are several solids, liquids, gases and even other matter that constitute our surroundings and can go from one state of matter to another without changing its chemical substance. Among all these let us understand the process of condensation and sublimation with examples.

Complete answer:
Condensation is the process of changing the state of matter from the gas phase into the liquid phase. It can also be defined as the change in the state of water vapour to liquid water.
$gas\xrightarrow{{Condensation}}liquid$
In the vapour form water molecules are arranged more randomly than in liquid form. As condensation occurs, water molecules become more organized and heat is released into the atmosphere which results in formation of liquid water.
Example: There are various examples of condensation. We observe this natural phenomenon many times around us like morning dew on the grass, clouds in the sky, fogging a mirror and moisture on car windows.

Sublimation: It is the transition of a state of matter directly from the solid to the gas state, without going through the liquid state.
$solid\xrightarrow{{Sublimation}}gas$
Sublimation is caused by the absorption of heat which provides enough energy for molecules to overcome the attractive forces among them and escape into the vapour phase.
Example: Dry ice, a frozen form of carbon dioxide when exposed to air directly changes its phase from solid-state to gaseous state which is visible as fog. Another well-known example is naphthalene which is an organic compound. This organic compound sublimes at a temperature of 176F to form vapours.

Note: Solids which have high pressure at their triple point show sublimation. The triple point is the point at which substance can exist in all three states of matter simultaneously. The ‘triple point of water’ is the point where one is interested in all ‘three phases’ of water at a certain ‘pressure and temperature’. It is called triple point because at a particular temperature and pressure for particular substances, solid, liquid, and vapor phases coexist in equilibrium or we can say that the point where liquid becomes stable is called the triple point.