Difference Between Homogeneous and Heterogeneous

The key difference between homogeneous and heterogeneous is that homogeneous materials and mixtures have the same uniform composition and properties throughout whereas heterogeneous materials and mixtures do not have either uniform composition or uniform properties.

Homogeneous and heterogeneous are two different words that we can distinguish by the context in which we use them. Materials, mixtures, reactions, etc. can be homogeneous or heterogeneous. But the difficulty in identifying the difference between these two mostly arises at the classification of mixtures.

CONTENTS

1. Overview and Key Difference
2. What is Homogeneous
3. What is Heterogeneous
4. Side by Side Comparison – Homogeneous vs Heterogeneous in Tabular Form
5. Summary

What is Homogeneous?

Homogeneous means that something is uniform throughout the system. When we consider homogeneous materials, its composition and properties are the same throughout. Metals, alloys, ceramics and plastics fall into the category of homogeneous materials. In this type of mixtures, we cannot identify the mixed substances because, throughout the mixture, it is in one uniform phase and we cannot observe the components individually.

For instance, we can take air or salt dissolved in water as homogeneous mixtures. Homogeneous liquid mixtures are “solutions”. Also, an alloy is a solid mixture that we can consider as a homogeneous mixture. Moreover, bronze is a solid solution of copper and tin. It is also a good example of this type of mixtures.

Further, we cannot separate the components in this mixture via mechanical methods. The particle size of a mixture affects the nature of homogeneity. In a homogeneous mixture, the particle size is in the atomic level or the molecular level. Moreover, when considering chemical reactions, homogeneous reactions occur at the same phase.

What is Heterogeneous?

Heterogeneous means there is no uniformity throughout the system. It is the opposite term of homogeneous. For example, composite fibreglass is a heterogeneous material. Unlike homogeneous materials, these materials have different structures and different compositions throughout.

If we take a heterogeneous mixture, it is apparent that it contains more than one component in the mixture. However, in some cases, components in heterogeneous mixtures are visible only at the microscopic level. Usually but not always, we can separate the components in this type of mixtures using a mechanical method. For instance, a mixture of water and sand, suspension of sulfur in water, and granite are heterogeneous mixtures.

In these mixtures, the properties are not uniform throughout; thus, we can separate the components in that mixture depending on the property variation. For example, we can separate a mixture of plastic and iron particles, which is a heterogeneous mixture based on their density variation or different magnetic properties. Heterogeneous mixtures contain larger particles. Suspensions also fall into this category. In the case of chemical reactions, heterogeneous reactions occur at different phases.

What is the Difference Between Homogeneous and Heterogeneous?

Homogeneous means that something is uniform throughout the system while heterogeneous means there is no uniformity throughout the system. Therefore, the key difference between homogeneous and heterogeneous is that homogeneous materials and mixtures have the same uniform composition and properties throughout whereas heterogeneous materials and mixtures do not have either uniform composition or uniform properties.

Moreover, we cannot separate the particles in homogeneous mixtures using mechanical methods. However, not always but most of the times we can separate particles in heterogeneous mixtures using mechanical methods. Another important difference between homogeneous and heterogeneous mixtures is that atomic or molecular level particles are present in homogeneous mixtures while in heterogeneous mixtures particles are larger than the atomic or the molecular level.

Summary – Homogeneous vs Heterogeneous

The terms homogeneous and heterogeneous describe the uniformity and non-uniformity of systems respectively. The key difference between homogeneous and heterogeneous is that homogeneous materials and mixtures have the same uniform composition and properties throughout whereas heterogeneous materials and mixtures do not have either uniform composition or uniform properties.

Reference:

1. Helmenstine, Anne Marie, Ph.D. “The Difference Between Heterogeneous and Homogeneous Mixtures.” ThoughtCo, Sep. 24, 2018. Available here   
2. “Homogeneous and Heterogeneous Mixtures.” Wikipedia, Wikimedia Foundation, 24 Nov. 2018. Available here  

Image Courtesy:

1.”Coloured-transition-metal-solutions” (Public Domain) via Commons Wikimedia 
2.”Orange juice 1 edit1″By Agency of the United States Department of Agriculture – USDA, (Public Domain) via Commons Wikimedia