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When you combine two or more materials, a mixture is formed; In chemistry, a mixture is called a combination that does not produce a chemical reaction. There are two categories of mixtures, homogeneous mixtures and heterogeneous mixtures. Below we show more specifically the two types of mixtures and some examples.
Important data:
- A mixture is formed by combining two or more materials.
- A homogeneous mixture appears uniform and always looks the same, regardless of the size of the sample that is observed.
- A heterogeneous mixture contains particles of different shapes or sizes, and the composition of one sample may differ from that of another sample.
- The appearance of a heterogeneous mixture depends on the distance from which it is examined; the sand may appear homogeneous from a distance, but when you zoom in on it, it is heterogeneous.
- Examples of homogeneous mixtures are air, a saline solution, and most alloys.
- Examples of heterogeneous mixtures are sand, oil, and water and chicken noodle soup.
Homogeneous mixtures
Homogeneous mixtures are a type of mixture in which its components are not distinguished, whose composition is uniform and in which each part of the solution has the same properties. They occur in a single phase, either in solid, liquid or gaseous form, regardless of the distance at which they are examined, since the chemical composition is the same for any sample in the mixture.
heterogeneous mixtures
Heterogeneous mixtures are not uniform, since they are formed from the union of two or more substances that are not chemically linked. They are not the product of any type of chemical reaction, and although the mixture itself may give rise to some type of reaction, if two samples are taken from different parts of the mixture, they will not have an identical composition. A mechanical method can be used to separate the components of a heterogeneous mixture, such as filtering rocks to separate them from sand.
Many times these mixtures are evident and the different types of materials are easily appreciated. For example, in a salad you can see vegetables of different sizes, shapes and classes, while in other cases you have to look more closely, even with the help of a magnifying glass or microscope, to recognize the mixture.
Any mixture that contains more than one phase of matter is a heterogeneous mixture. In this case the recognition can be complicated, since a change of conditions can alter a mixture. For example, an unopened soft drink in a bottle has a uniform composition and is a homogeneous mixture, but once the bottle is opened, bubbles of carbonation appear in the liquid. These are gases, while most of the soda is liquid. The mixture, then, has gone from being homogeneous to becoming heterogeneous.
References
- Natural Sciences, Santillana, 3rd year of Secondary Education. E. Vadillo et al . 1997
