A Soluble Separation Solution

Objective

In this experiment you will learn about soluble and insoluble chemicals, and use the difference in solubility of salt and pepper to separate the components of a mixture.

Introduction

Chemistry is the study of matter and how matter behaves and interacts with other kinds of matter. The way that matter behaves is called a "property" of matter. Everything around us is made of matter, and you can explore the properties of matter using some common chemicals around your home.

One important property of matter is called "solubility." We think about solubility when we dissolve something in water. If a chemical is soluble in water, then when you add it to water it will dissolve, or disappear. If it is not soluble, then it will not dissolve and you will still see it floating around in the water.

When you add a soluble chemical to dissolve in water you are making a "solution," and solutions are very important for chemistry. We call the chemical you are adding the "solute" and the liquid that it dissolves in the "solvent." Even though after a solute dissolves in a solvent it becomes invisible, it is still there. If you were to evaporate all of the liquid away from the solution, you would be left with your dry chemical again. In fact, this is how salt is processed in giant salt flats where seawater is slowly evaporated, leaving behind huge amounts of sea salt.

All of the different kinds of matter can be sorted into categories based upon whether they are soluble or not in different solvents. Because of this, the properties and solubility of different chemicals can be used to separate mixtures of chemicals. A chemical mixture is a blend of two or more different kinds of chemicals where the individual chemicals do not react with each other, but remain separate. You can see an example of this when you look closely at a dry mixture of salt and pepper.

In this experiment, you will use the different properties of the chemicals in salt and pepper to separate a mixture. By doing this, you will learn about the solubility of soluble and insoluble chemicals.

Terms, Concepts and Questions to Start Background Research

To do this type of experiment you should know what the following terms mean. Have an adult help you search the internet, or take you to your local library to find out more!

• chemical
• crystals
• mixture
• solution
• soluble
• solute
• solvent
• insoluble
• filtration
• evaporation