Phase Changes of Matter – Condensation, Sublimation, Deposition

Introduction

The matter is anything that has mass and occupies space. Matter cannot always be seen.  All matters are made up of tiny particles, such as atoms, molecules or ions. We all know that matter exists in different forms in our nature. As we know, that matter exists in four states: Solid, liquid, gas, and plasma, but on earth, matter exists in only three states. There are six different phase changes in the states of matter. 

A phase is a distinctive form of a substance, and matter can change among the phases. These changes can take place upon adding some external energies, temperature, and pressure. 

The six different changes of phases of matter which happens in between the substances are:  

1. Freezing 

2. Vaporization 

3. Melting 

4. Condensation 

5. Sublimation 

6. Deposition 

Explanation

Whenever the substances are subjected to certain conditions, change in phases takes place. As we generally know, that solid has to get into the liquid phase to reach the gaseous state. But there are some processes in which solids can be directly converted to gas or gas can be converted to solid.  

When a solid changes its state to a gas without going through the liquid phase, the process is called sublimation. In reverse, when gas changes to a solid without going into the liquid phase, the process is called deposition or re-sublimation. 

The process in which the physical state of matter changes from the gaseous state to the liquid state is known as condensation. For example: when water vapor (gas) present in the atmosphere changes to a liquid. This happens when the gaseous substance is cooled. 

Condensation: 

Condensation is the transformation from which water vapor converts to liquid. Whenever the water droplets in the cloud mix, the cloud becomes heavy to pour down the droplets. 

Whenever we are tired off, or we come home after playing in the ground, we feel thirsty, and we come over to the fridge and open the door. We see the water droplets on the bottle. How did the droplets come on it? The reason is that the particles inside the substances are condensed. 

Condensation is a phenomenon in which the complete heat is removed from the substance, and from there, it converts to liquid. 

Examples of condensation:  

1. Fog in the mirror: When the temperature gets cooler and less than the spheric temperature, the gas or the vapors are changed to fog. 

2. Water droplets on the bottle: When a bottle is taken from the refrigerator, as the water vapor gets condensed, it shows water droplets on the bottle. 

3. Clouds in the sky: These are formed when water gets cooled in the atmosphere. As the temperature gets lowered or less than normal, the water gets condensed.                 

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4. Moisture covering the car window:  

5. Fog on the spectacles 

Sublimation and Deposition

The process or transformation of a substance from solid state to a gaseous state without getting into the liquid state is known as sublimation. This is one of the examples of endothermic reactions.  

Examples: Best example for the sublimation is dry ice, naphthalene, and camphor. 

Dry ice is solid carbon dioxide. When dry ice is kept exposed to the air and to the atmospheric temperature, it directly changes its solid phase to the gaseous phase, which we can see in the form of fog.  

Naphthalene is one of the organic compounds. Naphthalene is used for pesticides, and it looks like a ball. This naphthalene is seen in the washbasins in hotels, restaurants and is of white color.  

Camphor is also one of the organic compounds. When we light the camphor, it directly gets into the gaseous form and mixes up with the air.   

Deposition is a process reverse to the sublimation, which means the gaseous phase directly converting or changing into the solid state without entering into the liquid. 

For example: Water vapor to ice – Water vapor transforms directly into ice without changing to a liquid, a process that often occurs on windows during the winter months. 

Physical vapor to film – thin layers of material known as ‘film’ are deposited onto a surface using a vaporized form of the film. 

Examples of Phase Changes 

Condensation: Dew is a common result of condensation caused by airborne water vapor. 

Deposition: Hoarfrost is a grayish-white frost that develops in cold, clear conditions when water vapor freezes. Silver vapor deposition onto glass to create a silver mirror is another illustration. 

Sublimation: Sublimation is the process through which dry ice transforms from solid carbon dioxide to carbon dioxide gas. Another illustration is the change on a chilly, windy winter day from ice to water vapor instantly. 

Summary

1. The matter is anything that has mass and occupies space. Matter cannot always be seen.
2. As we know, that matter exists in four states: Solid, liquid, gas, and plasma, but on earth,
   matter exists in only three states.
3. A phase is a distinctive form of a substance, and matter can change among the
   phases. These changes can take place upon adding some external energies, temperature,
   and pressure.
4. Condensation is a phenomenon in which the complete heat is removed from the
   substance, and from there, it converts to liquid.
5. The process or transformation of a substance from solid state to a gaseous state without
   getting into the liquid state is known as sublimation.

FAQs 

1. What is Condensation? 

Ans) Water vapour turns into liquid through the process of condensation. When the water droplets in the cloud combine, the cloud is heavy and the droplets fall off it. 

2. What is meant by sublimation? 

Ans) Sublimation is the transition of a substance from a solid to a gaseous state without passing through a liquid stage. 

3. Is sublimation being an endothermic reaction example? 

Ans) Yes, Camphor must be heated up in order to sublimate. It is therefore an endothermic reaction.