Experiment: Making salt:copper sulphate

Materials: Making a salt, copper sulphate

Materials: copper oxide, dilute sulphuric acid, plastic beaker, evaporating dish, filter funnel, filter paper, stirring rod, spatula/plastic teaspoon

Making copper sulphate

Method

1. Pour 20cm³ dilute sulphuric acid into a beaker
2. Add a small spatula load of copper oxide and stir well until it has all dissolved
3. Continue adding copper oxide until no more will dissolve
4. Filter the solution to remove the undissolved copper oxide
5. Collect the filtrate in an evaporating dish
6. Heat the filtrate in an evaporating dish until the mixture is saturated
7. Place the evapourating dish with the filtrate on a window and leave for a few days

Observation/Results

The saturated filtrate. Image credit scienceprojectlab.com

• The copper oxide reacts with the dilute sulpiric acid
• This gives the impression that the copper oxide is dissolving into the acid
• When the acid is completely neutralised copper oxide will no longer dissolve
• The saturated filtrate has a bluish colour which is different from that of the acid which is colourless and the copper oxide which is black in colour
• After a few days copper sulphate crystals form in the evaporating dish once the remaining water has evapourated

Conclusion

• Bases react with acids to form water and a salt
• The equation can be written as:
• \text{base+ acid}\rightarrow\text{salt+water}
• In this case sulphuric acid reacts with copper oxide to form copper sulphate and water
• The equation can be represented as:
• \text{sulphuric acid+copper oxide}\rightarrow\text{copper sulphate+water}
• The copper sulphate has a  blueish colour

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