Core practical - Making copper sulfate crystals

Question 1

Method: (7)

Answer 1

1- Place some sulfuric acid in a conical flask and warm it in a water bath.
2- Add a spatula of copper oxide powder to the acid and stir with a glass rod.
3- Continue adding copper oxide powder until it is in excess.
4- Filter the mixture to remove the excess copper oxide.
5- Pour the filtrate (the copper sulfate solution) into an evaporating basin.
6- Heat the copper sulfate solution to evaporate half of the water.
7- Pour the solution into a watch glass and leave to allow all of the water to evaporate.

Question 2

Explain why the sulfuric acid is warmed in a water bath in step 1.

Answer 2

Warm acid will react faster than cold acid, helping to make sure that all the acid reacts with the copper oxide.

Question 3

what are the 3 hazards in this practical?

Answer 3

Sulfuric acid
Boiling water bath
Hot copper sulfate solution spitting out during crystallisation

Question 4

possible harm and precautions for ‘Sulfuric acid’:

Answer 4

possible harm: Concentrated acid is corrosive and damages skin and clothes
precautions: Use dilute sulfuric acid

Question 5

possible harm and precautions for ‘Boiling water bath’:

Answer 5

possible harm: Skin burns

precautions: Ensure the boiling water bath is stable

Question 6

possible harm and precautions for ‘Hot copper sulfate solution spitting out during crystallisation’:

Answer 6

possible harm: Damage to eyes and skin

precautions: Wear eye protection and avoid standing over the hot apparatus