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

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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