You will identify homogeneous and heterogeneous mixtures and determine the appropriate methods to separate them.
After completing this tutorial, you will be able to complete the following:
A mixture is a combination of two or more substances that are not chemically combined. Since they still retain their own chemical properties, they can be separated by physical means. Mixtures fall into two different categories, homogeneous and heterogeneous. Homogeneous mixtures appear to be the same throughout (such as salt water). Heterogeneous mixtures have a variable composition throughout the mixture (such as sand).
Often, mixtures may need to be separated into their component substances. When separated, the individual substances will retain their chemical properties. Multiple methods may be used to separate mixtures including filtration, distillation, and separatory funnels.
Filtration is a method most commonly used to separate a solid-liquid mixture, where the solid has not dissolved but is suspended. Filter paper is placed on top of a collection device, and the mixture is poured into the filter paper. The solid will remain in the filter, and the liquid will run through the paper and into the collection device.
Distillation is a method that can separate a variety of mixtures including a solid-liquid solution, and two liquids with different boiling points. The liquid is placed in the distillation apparatus and heated. One of the components of the mixture vaporizes while the other remains in the initial container. The vapor moves into a collection tube, which cools the vapor, condensing it into a liquid. The condensed liquid is then collected in a separate container. Each component of the mixture is now separated and in individual containers.
Separatory funnels are used with two liquids that have different densities. The mixture is poured into the separation funnel where the liquids separate by densities. The stopcock is opened to allow the more dense fluid to run through. When the first liquid completely runs through, the stopcock is shut and the two liquids are separated.
|Approximate Time||20 Minutes|
|Pre-requisite Concepts||Learners should be familiar with the concept of solutions.|
|Type of Tutorial||Concept Development|
|Key Vocabulary||distillation, filtration, heterogeneous|