In chemistry, a mixture It is the combination of two or more pure substances that come together without changing chemically. For this reason, it is possible to separate the components of the mixtures by certain physical procedures, such as filtration or distillation. For instance: water and sand, coffee with sugar, oil in water.
In general, mixtures are classified into homogeneous and heterogeneous. Sometimes a third category is distinguished with intermediate characteristics: that of colloids. Mixes are found practically everywhere; many of the objects around us include mixtures, both homogeneous and heterogeneous:
- Homogeneous mixtures. They are mixtures that appear completely uniform, without discontinuities, which is why they are said to have a single phase. The substances that make up a homogeneous mixture are uniformly distributed. Solutions are typically homogeneous mixtures, and there are liquid, solid and gaseous solutions.
- Heterogeneous mixtures. They are mixtures in which it is possible to observe the discontinuity of their phases (every heterogeneous mixture has at least two phases) with the naked eye, although sometimes a device or equipment with a higher resolution than the human eye is necessary to appreciate and distinguish them. They are not uniform. Heterogeneous mixtures are often obtained when trying to bring together substances that are insoluble or immiscible. This causes the components to be separated and form different phases. By virtue of this non-uniform distribution, samples from different parts of a heterogeneous mixture can have different compositions.
The solutions are homogeneous mixtures, while the suspensions they are heterogeneous mixtures. But there is also a type of mixture that has intermediate properties between solutions and suspensions, and they are called colloids or colloidal systems. Examples of colloids are milk, gels, and emulsions.
Examples of mixtures
|Sugar in water||Hydrogen on Platinum||18 karat gold|
|Salt water (brine)||Mercury in silver||Ground|
|Air||Silver in Gold||Oxygen in water|
|Came||Kerosene in water||Alcohol in water|
|Tea||Wax and water||Salt and pepper|
|Bronze||Vinegar and oil||Granite|
|Detergent in water||Oil in water|
Examples of heterogeneous mixtures
|Lettuce and tomato salad||Water and sand||Stones and wood|
|Water and oil||Meat and potatoes||Papers and tapes|
|Air and land||Soup with noodles||Water and paraffin|
|Rice and beans||Wood and stones||French fries and peanuts|
|Vinegar and oil||Sausages with mayonnaise||Water and stones|
|Water and gasoline||Potatoes and egg||Milk with marshmallows|
|Cookies with sweet and butter|
Examples of homogeneous mixtures
|Baking soda in water||Diluted bleach||Cough syrup|
|Cooking oil mix||Tincture of iodine||Coffee with sugar|
|Blood||Bronze||Detergent with water|
|Toilet soap||Mayonnaise||Hair dye|