Post on 18-Nov-2014
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04/08/23
Compounds and Compounds and MixturesMixtures
W Richards
Worthing High School
04/08/23
ElementsElementsIf 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
04/08/23
CompoundsCompoundsCompounds are different to elements. They contain different atoms. Here are some examples:
Glucose
Methane
Sodium chloride (salt)
04/08/23Some simple Some simple compounds…compounds…
Methane, CH4 Water, H2O
Carbon dioxide, CO2
Ethyne, C2H2Sulphuric
acid, H2SO4
Key
Hydrogen
Oxygen
Carbon
Sulphur
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Making compoundsMaking compoundsCompounds are made when two or more elements (or
compounds) go through a chemical reaction.
For example:
1) When carbon reacts with oxygen it usually forms ____ _________
2) When oxygen reacts with hydrogen it could form ______
3) 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?
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Naming compoundsNaming compoundsRule 1 – When two elements join the end is
usually _______ide.
e.g. Magnesium + oxygen magnesium oxide
1) Sodium + chlorine
2) Magnesium + fluorine
3) Lithium + iodine
4) Chlorine + copper
5) Oxygen + iron
6) KBr
7) LiCl
8) CaO
9) MgO2
10)KF
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Naming compoundsNaming compoundsRule 2 – When three or more elements combine and one of them is oxygen the
ending is _____ate
e.g. Copper + sulphur + oxygenCopper sulphate
1) Calcium + carbon + oxygen
2) Potassium + carbon + oxygen
3) Calcium + sulphur + oxygen
4) Magnesium + chlorine + oxygen
5) Calcium + oxygen + nitrogen
6) AgNO3
7) H2SO4
8) K2CO3
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Naming compoundsNaming compoundsRule 3 – If two identical elements combine
then the name doesn’t change
This happens with the following elements:
1) H2
2) N2
3) O2
4) F2
5) Cl2
6) Br2
These elements always go around in pairs. For example, hydrogen looks like this:
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MixturesMixtures
100 g
105 g
Before After
04/08/23Element, mixture or Element, mixture or compound?compound?
Salty water Hydrogen
Hydrochloric acid
Sodium chloride (salt)
Diamond
Air
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AirAirAir is a mixture…
79% 79%
21% 18%0.03%
1%
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Liquid air
Separating airSeparating airAir 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
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
Oxygen
Argon
Nitrogen