Page 101 - Science Coursebook

7.3 Metal carbonates and acids

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3 Add more copper carbonate until it stops reacting. You
should have a small amount of unreacted copper carbonate
left in the beaker. (This is called adding excess copper
carbonate. It makes sure that all the acid
has reacted.)
4 Filter the mixture. The unreacted copper carbonate will be

trapped in the filter paper.

5 Pour the filtrate into an evaporating basin and heat it gently.
Safety: Take care while you heat this as the solution may
spit and burn you.

6 Stop heating the dish when you see some crystals around filtrate
the edge of the solution.
7 Leave the solution for a few days to cool and
evaporate slowly.
Questions
A1 What did you observe when you added copper carbonate to the
hydrochloric acid?
A2 Which gas is given off during this reaction?

A3 Describe the appearance of the copper chloride that you have made.
A4 Write the word equation for your reaction.
A5 Which substances in your word equation are salts?
A6 Using your observations from this experiment, what can you say about the
solubility of copper carbonate and copper chloride? (Think about what

happened when you filtered the liquid from the beaker.)
A7 Suggest how you could use copper carbonate to make copper sulfate.

Blue-green colours in these rocks in the Atacama
Desert in Chile tell you that they contain copper
salts. This bright blue-green mineral in the rock is
called malachite. It is made from copper carbonate.

Summary
• Salts can be formed by the reaction of acid on a carbonate.
• acid + carbonate → salt + water + carbon dioxide

7 Salts 99