1. Energy and reactions: Make sure you revise:
Exothermic and endothermic reactions
Reversible reactions
Test for water
The Haber process
Using ammonia

2. Exothermic and Endothermic Reactions
In an exothermic reaction:
heat is given out
temperature of the surroundings increases.
In an endothermic reaction:
heat is taken in
temperature of the surroundings decreases.

3. Anhydrous Copper Sulphate Hydrated Copper Sulphate
Reversible Reactions
This is the symbol for a reversible reaction:
Reversible reactions are exothermic in one direction and endothermic in the other direction
An example of a reversible reaction is when hydrated copper sulphate is heated to produce anhydrous copper sulphate. When this is left to cool it turns back into hydrated copper sulphate.
The reverse reaction is used as a test for water. When water is added to anhydrous copper sulphate, 2 things happen:
1.) White solid turns blue, 2.) Reaction gives out heat. It’s an exothermic reaction
(Takes in) Heat
Endothermic
Anhydrous Copper Sulphate
(White Solid)
Hydrated Copper Sulphate
(Blue Solid)
(Cool + Steam)
Exothermic

4. Ammonia Ammonia dissolves in water to produce an alkaline solution
Ammonia reacts with acids to produce ammonium salts
Ammonium salts are important because they are used by farmers as fertilisers to help crops grow.

5. The Haber Process – making ammonia (NH3)
The Haber Process uses nitrogen (from the air) and hydrogen (from natural gas) to produce ammonia which can be used to make fertilisers.
The reaction uses a high temperature (450°C), high pressure (200 atmospheres) and an iron catalyst to produce a reasonable yield of ammonia.
After they leave the converter, the gases are cooled, ammonia is removed as liquid and any unreacted nitrogen and hydrogen are recycled.
The yield is less than 20% but the ammonia is produced quickly and no gases are wasted

6. Conditions in the Haber process Higher tier
Exothermic  forward reaction
N2 + 3H2  2NH3
4 molecules
of gas
2 molecules
of gas
Backwards reaction  Endothermic
Condition
Action
Effect
Yield in the Haber Process:
Temperature
Increase
Moves in endothermic direction
More reactants (Nitrogen and Hydrogen)
Decrease
Moves in exothermic direction
More product (ammonia)
Pressure
Moves in direction where there are LESS molecules
Moves in direction where there are MORE molecules

7. Dynamic equilibrium and change
Teacher notes
This completing sentences activity could be used as a plenary or revision exercise on dynamic equilibrium. Students could be asked to write down the missing words in their books and the activity could be concluded by the completion on the IWB.