Mixtures and Solutions


   All matter can be classified as either a mixture or a pure substance. There are many more mixtures then pure substances.

   1) Mixture - A mixture contains two or more different types of matter. For example: salt water is a mixture containing salt and water.

   If a substance has more than one type of properties, it is a mixture. For example: In trail mix there are different colours, different textures, different flavors, etc, so it is a mixture.


   2) Pure Substance - A pure substance is matter that is the same throughout. For example: salt, gold and distilled water are pure substances.


How pure substances are different than mixtures?


   A pure substance contains only one type of particles. For example: gold contains only Au particles, water contains only H2O particles( hydrogen and oxygen).

   A mixture contains more than one type of particle. Each particle in a mixture keeps it's own properties which changes the properties of the mixture. For example water boils at 100 degrees, salt boils at 1500 degrees. When we mix them, salt water boils at 103degrees.


    Homogeneous/ Heterogeneous   


Mixtures can be classified as either homogeneous or heterogeneous.

   Homogeneous mixture- This is a mixture where the parts appear to be the same throughout. For example: salt water, air, steel, lemonade .


   Heterogeneous mixture- This is a mixture that is made up of two or more parts that can be seen.For example: oil and water, concrete, humans


   Some substances fall in between. They are part heterogeneous and part homogeneous. For example orange juice.


   Heterogeneous mixtures are sometimes called Mechanical Mixtures, if the parts are easily seen and separated. For example: a pizza is a mechanical mixture because we can see the different parts and separate them.


   Homogenous mixtures are also called solutions. A solution is a mixture that contains two or more substances that are combined, but it looks as if there is only one substance-even under a microscope. 
   A solution that is made from two or more metals is called an Alloy. Some examples of alloys are steel, brass, and bronze.



   Some examples of different solutions are:

       Liquid -- pepsi,  kool-aid

       Gas -- air

       Solid -- steel,   brass


   There are various ways to tell the difference between a heterogeneous mixture and a solution.


   One is to use a microscope to see if there are different particles.

   Another way is to use a filter to see if you could separate out particles.

   Finally, we could shine a light through the substance.

   - If it is a solution the light will shine straight through

   - If it is a mixture the light will reflect off particles in the mixture and we would see the beam of light.