To explain vapour and gas: Understanding the states of matter is crucial in studying chemistry. Matter can exist in three primary states: solid, liquid, and gas. However, within the gaseous state, two terms are often used interchangeably: vapour and gas. Understanding the characteristics of vapour and gas is a big part of chemistry, and it's essential for students studying for tests like NEET and JEE. In this article, we'll look at some of the most important differences between vapour and gas.
Vapour refers to the gaseous state of a substance that is typically found as a liquid or solid at room temperature and atmospheric pressure. It is formed when a substance undergoes evaporation or sublimation. Evaporation occurs when a liquid changes into a gas at temperatures below its boiling point, while sublimation is the direct conversion of a solid into a gas without passing through the liquid phase.
Characteristics of Vapour:
Formation: Vapour is specifically formed from substances that have a boiling point or sublimation point below the current temperature and pressure conditions.
Composition: Vapour retains the same chemical composition as the liquid or solid from which it originated.
Condensation: Vapour can condense back into its liquid or solid state when it comes into contact with a cooler surface or when the temperature and pressure conditions change.
Density: Vapours generally have a lower density compared to gases since they are often formed from liquids or solids that are denser than gases.
Visibility: Vapours are often visible, appearing as clouds or fog due to the presence of tiny liquid or solid particles within them.
Gas refers to the gaseous state of matter, which can be found at room temperature and atmospheric pressure or obtained by heating a solid or vaporising a liquid. Unlike vapour, gases do not necessarily originate from liquids or solids and can exist independently.
Characteristics of Gas:
Origin: Gases can be obtained from various sources, including evaporation, sublimation, combustion, or directly from chemical reactions.
Composition: Gases can consist of individual atoms or molecules and may have a different composition than the substances from which they are derived.
Expansion: Gases have the ability to expand to fill the available space uniformly.
Compressibility: Gases are highly compressible, meaning their volume can be significantly reduced under increased pressure.
Homogeneity: Gases exhibit a high degree of homogeneity, with their constituent particles being evenly distributed throughout.
Vapour and Gas Difference
Vapour and gas are two terms used to describe the gaseous state of matter. Vapour refers to the gaseous state of a substance that is usually a liquid or solid at room temperature, while gas is a more general term that can include substances that exist in the gaseous state independently. Vapours have a specific origin and composition, while gases can originate from various sources and have different compositions. vapours can condense back into their liquid or solid state, while gases lack this ability under normal conditions. Furthermore, vapours can be visible and may contain liquid or solid particles, while gases are typically invisible and homogeneous. Finally, vapours have a lower density and are less compressible compared to gases. Understanding these differences is essential for a comprehensive understanding of the gaseous state of matter in the context of class 12 chemistry.