Tuesday 20 September 2011

Classification of Matter:


Yesterday in Chem11 we learned about the classifications of Matter...

Here are some notes

We can divide matter into two main types of Substances:

 Homogeneous
- One type of substance that we can see (ex. Distilled Water, Milk, Oxygen, Graphite)



Heterogeneous
- Contains more than one visible component (ex. Sand, Blood, Granite, Chocolate chip cookie)




Below is a chart that helps describe how Matter is classified:




From the branch "Homogeneous Substances" comes two other branches.  

  1. The first is labeled Pure Substances. There are 2 types of pure substances...
  •  Elements - substances that cannot be broken down into simpler substances by chemical reactions (ex. Oxygen, Iron, Magnesium).
  • Compounds - Substances that are made up of 2 or more elements and can be changed into elements (or other compounds) by chemical reactions (ex. Sugar, Water).
* How do you tell the difference?  
  • Often VERY difficult to tell the difference between Elements and Compounds (their differences are only 'visible' on the atomic level). 
  • However you can use Electrolysis to help you.  

Pretty cool right?! :)

     2.  The second branch is labeled Homogeneous Mixtures
  • in Homogeneous Mixtures, the different parts are not visible. 
  • a Solution is a homogeneous mixture of 2 or more substances.
  • Solutions usually involve liquids but don't necessarily have to (ex. Fog, Steel). 
  • The component of a solution which is present in greater amount is the Solvent (Water = most common solvent). 
On the other side of the diagram is the category "Heterogeneous Substances" which links the last branch. 

  1. The last branch we talked about was called Mechanical Mixtures.  We didn't go into too much detail about it but it's basically this...
  •  a mixture whose components can be separated by mechanical means.
This leads us to our last topic which is Separating Mixtures.   There are many ways to do this but it depends on the type of mixture.  For example, Filtration is used for Heterogeneous mixtures only.  The other four listed in our notes are "by hand, distillation, crystallization, and chromatography.  All of these are 'Physical Changes.'

Here's a video on some of the different ways you can separate mixtures:



 Have a great day!


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