1. Compounds and Mixtures
19/09/2018
Compounds and Mixtures
W Richards
Worthing High School

2. These atoms are ALL iron – there’s nothing else in here
Elements
19/09/2018
If a solid, liquid or gas is made up of only one type of atom we say it is an element. For example, consider a tripod made up of iron:
These atoms are ALL iron – there’s nothing else in here

3. Sodium chloride (salt)
Compounds
19/09/2018
Compounds are different to elements. They contain different atoms. Here are some examples:
Sodium chloride (salt)
Methane
Glucose

4. Some simple compounds…
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Methane, CH4
Carbon dioxide, CO2
Water, H2O
Key
Hydrogen
Oxygen
Carbon
Sulphur
Sulphuric acid, H2SO4
Ethyne, C2H2

5. Water, iron oxide or carbon dioxide?
Making compounds
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Compounds are made when two or more elements (or compounds) go through a chemical reaction.
For example:
When carbon reacts with oxygen it usually forms ____ _________
When oxygen reacts with hydrogen it could form ______
When iron reacts with oxygen it could form ______ ______
There are usually “tell-tale” signs to show when a compound is being made, such as bubbling, heat given off, colour changes, fizzing etc.
Water, iron oxide or carbon dioxide?

6. Rule 1 – When two elements join the end is usually _______ide.
Naming compounds
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Rule 1 – When two elements join the end is usually _______ide.
e.g. Magnesium + oxygen magnesium oxide
Sodium + chlorine
Magnesium + fluorine
Lithium + iodine
Chlorine + copper
Oxygen + iron
KBr
LiCl
CaO
MgO2 KF

7. e.g. Copper + sulphur + oxygen Copper sulphate
Naming compounds
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Rule 2 – When three or more elements combine and one of them is oxygen the ending is _____ate
e.g. Copper + sulphur + oxygen Copper sulphate
Calcium + carbon + oxygen
Potassium + carbon + oxygen
Calcium + sulphur + oxygen
Magnesium + chlorine + oxygen
Calcium + oxygen + nitrogen
AgNO3
H2SO4
K2CO3

8. Naming compounds
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Rule 3 – If two identical elements combine then the name doesn’t change
This happens with the following elements: H2 N2 O2 F2
Cl2
Br2
These elements always go around in pairs. For example, hydrogen looks like this:

9. Mixtures
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Before
After
100 g
105 g

10. Element, mixture or compound?
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Salty water
Hydrogen
Hydrochloric acid
Air
Diamond
Sodium chloride (salt)

11. Air
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Air is a mixture… 1%
21%
18%
0.03%
79%
79%

12. Fractional distillation
Separating air
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Air can be separated into the different gases that make it up. To do this you first have to cool air down to -2000C and turn it into a liquid:
Fractional distillation
Nitrogen
Liquid air
Argon
Oxygen
In this chamber the air is gradually heated up again and the different parts of air “distil” off at different temperatures according to their boiling points