Distinguishing between homogeneous and heterogeneous mixtures is a matter of the scale of sampling. On a small enough scale, any mixture can be said to be heterogeneous, because a sample could be as small as a single molecule. In practical terms, if the property of interest is the same regardless of how much of the mixture is taken, the mixture is homogeneous. Some mixtures can be separated into their components by physical mechanical or thermal means.
Boundless vets and curates high-quality, openly licensed content from around the Internet. This particular resource used the following sources:. Skip to main content. Introduction to Chemistry. Search for:. Substances and Mixtures. Learning Objective Distinguish chemical substances from mixtures. Key Points Matter can be broken down into two categories: pure substances and mixtures. And I should probably do bronze in a more bronze color right over here. But if you were to look at it with a very sensitive microscope or based on the models that we now know what is going on in that metal, in that alloy, what's happening is you actually have a mixture of metals.
But it is a homogeneous mixture of metals because at a macro level, you can't really see the differences. Now at a micro level, you can, because there are different metals mixed in together in this alloy.
Now, as can imagine you also have liquid solutions and in chemistry, these are the ones that we'll often deal most. We will also deal with solid and gas solutions as well. And when I think of a homogeneous liquid mixture or a liquid solution, the one that comes to mind for me, but we'll see a lot of these in our journey through chemistry is salt water. Salt water. Salt water has sodium chloride dissolved in water. And if you were to go to the ocean, and if you were to just look at the salt water, or if you were to measure its properties, even in a lab, you would see that the properties throughout the salt water seem to be uniform.
At a macro level, it appears to be homogeneous. It appears to be uniform. But if you were to look at what's happening at an atomic level, you would see that you have your water molecules. Let me draw the water like that. That is the oxygen, each of them has two hydrogens. And this end is partially positive, we've seen this multiple times, the hydrogen end, the oxygen end is partially negative.
And so when you dissolve the sodium chloride, the chloride anions are attracted to the positive ends of the water. So maybe you have a chloride anion there. Rarely do we eat only one ingredient. For example, we can eat plain chicken, but why not mix it with a little seasoning? Food mixtures are often heterogeneous mixtures. A heterogeneous mixture is such that the components can be separated from one another.
A bowl of Cheerios, for example, is heterogeneous because you can literally pull out the individual pieces of cereal from the milk. Beyond the things we eat, our environments are full of other mixtures. Here are a few more examples:. Here are 10 examples of mixtures and a look at whether they are homogeneous or heterogeneous.
A homogeneous mixture is one which appears to have uniform composition. Samples taken from different parts of a homogeneous mixture have the same chemical composition. A homogeneous mixture consists of a single phase e.
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