![MCQs [2024]](https://engineeringinterviewquestions.com/wp-content/uploads/2021/02/Interview-Questions-2.png)
Solid, liquid, and gas are the three fundamental states of matter. However, you can classify the matter in pure substances and mixtures as well. Substances that have a particular composition get called as pure substances. They cannot get separated into other forms of matter. Elements and compounds are the two categories to classify pure substances further. When two or more pure substances come together, we call it a mixture. Mixtures can get divided into two kinds, namely, homogeneous and heterogeneous mixtures. In this article, you will learn about the difference between pure substance and mixture and fundamental concepts of the same.
Pure Substances and Mixtures
Before we dive into the pure substance vs mixture comparison, you must know some essential concepts. It’s important to understand what pure substance is, what a mixture is and how do they get classified further.
So as you know, all the substances can get divided into two categories – pure substance and mixture. Here, we will study both categories.
Pure Substance
The substances that contain only one type of particle and are free from any mixture, are known as pure substances. Gold, silver, iron, and aluminium are pure substances, to name a few. By their chemical composition, pure substances can be divided into two types – elements and compounds.
-
Elements – An element is a pure substance that contains a single kind of atom. Such a substance cannot be broken into two or a simpler substance by physical or chemical means. For instance, when you break down gold, you get gold again. Elements can be metals, non-metals, and metalloids.
-
Compounds – Compound is a pure substance; that is composed of many identical molecules and molecular entities that are composed of atoms that belong to more than one element held together by a chemical bond. Ionic compounds are held together by ionic bonds. Thus the atom of only one element that composes an entire molecule is not referred to as a compound.
Mixtures
Mixtures refer to substances that contain two or more different chemical substances that are not chemically combined. The physical combination of two or more substances is a mixture where the identities of the individual components are retained while the mixture is in form of colloid, suspension or solutions. A solution of salt and water, sugar and water, air, different gases, etc. is an example of mixtures. Based on their compositions, mixtures can get divided into two types – homogeneous and heterogeneous mixtures.
-
Homogeneous Mixtures – Those mixtures whose composition is uniform throughout the mixture is called homogeneous mixtures. Soda water, lemonade, a mixture of salt in water are a few examples of homogeneous mixtures.
-
Heterogeneous Mixtures – Those mixtures which do not have a uniform composition entirely are heterogeneous mixtures. A mixture of oil and water, soil, and sand are heterogeneous mixtures as they don’t have a uniform composition.
Difference Between Pure Substance and Mixture
|
Property |
Pure Substance |
Mixture |
|
Definition |
substances that are made up of only one kind of particle and has a fixed or constant structure |
Mixtures refer to substances that contain two or more different chemical substances that are not chemically combined together. The physical combination of two or more substances is a mixture where the identities of the individual components are retained while the mixture is in form of colloid, suspension or solutions. |
|
Categories |
They are classified into elements and compounds based on their compositions. |
Based on their composition, mixtures get divided into homogeneous and heterogeneous mixtures. |
|
Physical properties |
The physical properties of pure substances are definite and constant. |
Mixtures have varying physical properties. |
|
Chemical properties |
The chemical properties of pure substances are constant and definite too. |
Mixtures have variable or indefinite chemical properties. |
|
Separation |
It cannot be separated into pure substances using physical methods. |
It can be separated into mixtures using physical methods like evaporation, magnetic separation, etc. |
|
Examples |
Gold, oxygen, iron, water |
Oil and water, sand and soil, sugar solution |
Key Points
-
The matter is divided into two basic categories as pure substance and mixtures. The pure substances are further subdivided into elements and compounds. Mixtures are physically combined substances that can easily be separated into their primary substances.
-
There can be one or more types of atoms or molecules in the composition of the chemical compound.
-
There are different kinds of atoms and molecules that are present in the composition of the mixtures that are not chemically bonded.
-
A heterogeneous mixture is a mixture of two or more components where the components can be easily distinguished visually.
-
A homogeneous mixture is a mixture of different types of matter. Thus, matter can be in the same phase or in two different phases when separation is taking place.
Hence article is useful for students to understand the difference between pure substance and mixture. The difference is given in a tabular form which is quite convenient to compare the differences.