# Difference Between Homogeneous and Isotropic

## Main Difference – Homogeneous vs Isotropic

Uniformity is the quality of being uniform of something. Homogeneous refers to the uniformity of the structure of a particular substance. Isotropic materials are substances having physical properties that are equal in all directions. Thus, the main difference between homogeneous and isotropic is that homogeneous refers to the uniformity of structure and isotropic refers to the uniformity of physical properties.

## Key Areas Covered

1. What is Homogeneous
– Definition, Properties, Examples
2. What is Isotropic
– Definition, Properties, Examples
3. What is the Difference Between Homogeneous and Isotropic
– Comparison of Key Differences

Key Terms: Homogeneous, Isotropic, Molarity, Precipitate, Suspension, Uniformity

## What is Homogeneous

Homogeneous refers to the uniformity of the structure of matter. Some substances are composed of small units that are uniformly distributed throughout the volume of that substance. Therefore, the composition of a unit volume is equal to the composition anywhere in that substance.

For example, an aqueous solution of glucose is a homogenous mixture since glucose is well dissolved in water and glucose molecules are distributed all over the solution evenly. Therefore, a unit volume of glucose solution is composed of a particular amount of glucose molecules and it will be the same anywhere in that solution.

If the mixture is not homogeneous, then there will be either a precipitate or a suspension. Then it is called a heterogeneous mixture. In heterogeneous mixtures, the composition of the solution is different from one place to another.

Figure 1: A solution of KMnO4 is Homogeneous

The concept of molarity is applied for homogeneous solutions. The molarity of a solution is the amount of solute (in moles) present in one liter of solution. Therefore, the molarity of a solution gives the amount of solute present at any given point in that solution.

## What is Isotropic

Isotropic refers to a particular substance having uniform physical properties in every direction. In other words, isotropic materials have same values for thermal and mechanical properties in all direction.

As an example, a mixture of gases is isotropic. That is because, if heat is applied to that gas mixture, that heat will spread everywhere in that gas and the temperature of that gas mixture would be the same at every point of that mixture.

Figure: A piece of glass

Isotropic material can be either homogeneous or non-homogeneous. For example, glass (in the above image) and steel are non-homogenous material but are isotropic. When a uniform pressure is applied on steel, every point will deform in equal amounts.

## Difference Between Homogeneous and Isotropic

### Definition

Homogeneous: Homogeneous refers to the uniformity of the structure of matter.

Isotropic: Isotropic refers to the property of having uniform physical properties in every direction.

### Structure

Homogeneous: The structure of homogeneous material is uniform.

Isotropic: The structure of isotropic material can be either homogeneous or non-homogeneous.

### Direction

Homogeneous: The properties of homogeneous matter does not depend on the direction.

Isotropic: The properties of isotropic matter depends on the direction.

### Examples

Homogeneous: Homogeneous mixtures such as clear solutions, air are good examples for homogeneous materials.

Isotropic: Some homogeneous materials and some non-homogeneous materials are isotropic such as water(homogeneous) and glass (non-homogeneous).

### Conclusion

Substances can be categorized mainly into two groups as homogeneous matter and heterogeneous matter. But some materials can be grouped as isotropic because they show the same value for their physical properties in all directions. The main difference between homogeneous and isotropic is that term homogeneous refers to the uniformity of structure and isotropic refers to the uniformity of properties.

##### References:

1. “Isotropy.” Isotropy | [email protected] N.p., n.d. Web. Available here.  10 July 2017.
2. YourDictionary. “Examples of Homogeneous Mixture.” YourDictionary. N.p., 17 Apr. 2013. Web. Available here. 10 July 2017.

##### Image Courtesy:

1. “Potassium-permanganate-solution” By Coloured-transition-metal-solutions.jpg: Benjah-bmm27derivative work: Armando-Martin (talk) – Coloured-transition-metal-solutions.jpg (CC BY-SA 3.0) via Commons Wikimedia
2. “1476905” (Public Domain) via Pixabay