The differences between homogeneous and heterogeneous mixtures are based on the visibility of their components, ease of separation and preservation of properties.
It is well known that mixtures are made up of two or more substances, but there are two types of mixtures that can arise from these combinations.
Homogeneous mixture
In homogeneous mixtures, the conditions and properties of the compounds allow them to mix to the point that they cannot be distinguished from one another, as is the case with mayonnaise.
Heterogeneous mixture
In heterogeneous mixtures, the compounds that form it mutually repel each other due to the nature of their bonds, as is the case with water and oil.
Below are the differences between homogeneous and heterogeneous mixtures:
Visibility
In heterogeneous mixtures, the components that make up the mixture can be clearly seen. They are not evenly distributed.
In homogeneous mixtures, the components that make up the mixture cannot be clearly distinguished. They are evenly distributed, so that they appear to be a single substance to the eye.
A clear example between these two can be done with drinks. A homogeneous mixture could be a lemonade where at all points of the mixture it looks the same, while a heterogeneous mixture could be a clericot where the fruit is still distinguishable from the rest of the liquid
Separation
Heterogeneous mixtures are easy to separate into their original components. If the mixture is liquid and solid, a filtration can be done.
Depending on the size of the solids and if it is a liquid-liquid mixture, a decantation can be made.
In homogeneous mixtures the mixtures are difficult to separate into their original components. The best known method for a liquid-liquid mixture is that of distillation.
At an industrial level there is also distillation, but there are also methods such as absorption, separation by membranes, among others.
Properties
Each component of a heterogeneous mixture retains its individual properties because they are still dispersed.
Each part of a homogeneous mixture has similar chemical and physical properties. An example of this can be water and salt.
Water by itself does not conduct electricity, but when a certain amount of solute is added, in this case salt, a homogeneous mixture is formed with the physical ability to conduct electricity.
Chemical solutions
All chemical solutions are examples of homogeneous mixtures.
There is a whole part of analytical chemistry that is dedicated to studying these types of mixtures based on their concentrations, solubility constants and other terms.
Examples
Some examples of homogeneous mixtures are drinking water, spirits, vinegar.
Some examples of heterogeneous mixtures are metal alloys, some colloid suspensions or non-polar with polar substances, such as water with oil. In food we can find examples such as salads, among others.
References
- Hurtado Melo, S., & e-libro, C. (2012). Basic operations of the process, mixtures and solutions (UF0227). Malaga: IC Editorial.
- Uhl, VW, & Gray, JB (1966). Mixing: Theory and practice. New York: Academic Press.
- Sánchez, CA, Rodríguez, G., & Gómez, M. Á. (2012). Geometric tools for the basic design of distillation columns with ternary heterogeneous azeotropic mixtures. i. calculation of minimum reflux. EIA Magazine, (18), 143.
- Elements, compounds and mixtures: Basic chemistry. Jerome, BA and Quality Films SA de CV (Directors). (2007). Mexico: Quality Films.
- Lei, Z., Dai, C., & Chen, B. (2014). Gas solubility in ionic liquids. Chemical Reviews, 114 (2), 1289-1326. doi: 10.1021 / cr300497a