2. Chemical Reactions - Reactants and products
In a chemical reaction, one or more new substances are always formed.
The starting substances used in a reaction are the reactants.
The new substances formed in a reaction are the products.
reactants
products
The arrow means ‘change into’. In a chemical reaction, the reactants change into the products.
REACTANTS react; PRODUCTS are produced
It is often difficult to reverse a chemical reaction and change the products back into the reactants.

3. For each practical follow the instructions carefully.
Record the temperature at the start and the temperature it reaches to calculate the overall temperature change.
Ensure you allow time for the thermometer to reach temperature (30 seconds)
Practical 1:
Add copper sulphate solution to 1/3 depth of a boiling tube.
Take initial temperature
Add 1 spatula of Magnesium granules to the copper sulphate.
Take final temperature
Practical 2:
Add water 1/3 depth of a boiling tube.
Add 5 spatulas of Ammonium Nitrate granules to the
water.
Collect results and discuss outcomes.

4. Making use of Exothermic and Endothermic reactions