Mixtures
Many of the things we deal with every day are mixtures. A mixture is a when two or more substances are combined, but not chemically combined. This means that the mixing can be reversed without a chemical reaction needing to take place. There are two main types of mixtures – homogenous and heterogenous. They are distinguished by the manner in which the substances combine.
A homogenous mixture is a mixture in which the two substances mix well enough that the mixture is uniform all throughout. The particles mix well enough to come up with a stable mixture in which the particles cannot be divided through simple filtration. It is often called a solution. An example of a homogenous mixture is anything with a solute and a solvent like sugar and water.
A heterogenous mixture is a mixture in which the two substances mix well, but not enough for it to be completely uniform throughout the mixture. The uneven distribution of the two substances is due to the particle sizes or the phases and so the substances cannot blend together. To help see how this happens, think of anything that is literally “suspended” in water like algae in the ocean of milk of magnesia.
Colloids are a kind of sub‐type of mixtures. It is a mixture in between a solution and a suspension. It happens when the particles of one substance cannot be completely dissolved into the other substance, but can be distributed uniformly throughout. For example, facial wash with scrub particles are usually colloids because the substances are distributed uniformly, but some particles are not completely dissolved.
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