Pure substances and mixtures

Form 3 chemistry

Pure substances and mixtures

CXC OBJECTIVES: 2.1 Distinguish between pure substances and mixtures, 2.2 Distinguish between solutions, suspension and colloids. 2.3 Identify different types of solutions

CLASSIFICATION OF MATTER CHART. Click on each box and + to learn more

MATTER

PURE SUBSTANCES

MIXTURES

COMPOUNDS

ELEMENTS

HETEROGENEOUS MIXTURES

HOMOGENEOUS MIXTURES

What do you understand by this chart? Click the + below to see the answer

TEST YOURSELF!!

After reviewing the chart on the previous page, you should be able to tell the differnce between elements, mixtures and compounds. Click the + sign to see if you are right

comparison

Compounds

Mixtures

• Easily separated by physical means, no chemical reaction is needed

• The amounts of each substance in the mixture can vary e.g. in a salt and water mixture you can add any amount of salt
• or water to make a salt/water mixture

• The properties of the individual substances making up the mixture do not change when the substances are mixed together. e.g. the salt in the salt/water mixture is still salt and water is still water even though they are mixed together

• Not easily separated, a chemical reaction is needed

• The amount of each element in the compound is fixed e.g. water is H2O meaning it always has 2 hydrogen atoms and 1 oxygen atom

• The properties of the elements making up the compound are different from the compound. H2 and O2 by themselves are both gases, but when they are chemically bonded they make H2O which is a liquid .

vs

HOMOGENEOUS MIXTURES

A homogeneous mixture is uniform throughout and you cannot distinguish the components from each other. Solutions are examples of a homogeneous mixture. Solute+solvent=solution Did you know there are different types of solutions. Click here to learn more.

HETEROGENEOUS MIXTURES

Suspensions are heterogeneous mixtures where one substance does not dissolve in the other. Colloids are heterogeneous mixtures which have properties intermediate between that of a solution and a suspension Click here to see more

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