RP: Making Salts

Question 1

What does copper oxide and sulphuric acid produce?

Answer 1

Copper oxide+ sulphuric acid –> Copper sulphate + Water

Question 2

Why do you heat the acid at the beginning of the experiment?

Answer 2

To speed up the rate of reaction with the base.

Question 3

What is meant to add in “excess?”

Why is the base added in “excess? “

Answer 3

Excess: Add more than needed to fully react

To ensure it has fully reacted with the acid so no dangerous fumes are released when heating.

Question 4

Why is the mixture of solid metal oxide and salt solution filtered?

Answer 4

This separates the insoluble metal oxide from the salt solution.
This leaves a salt + water

Question 5

Why is the salt solution heated?

Answer 5

This causes the water to evaporate, leaving salt crystals.

Question 6

Why is the salt solution heated gently on a water bath?

Answer 6

To ensure none of the crytstals break down.

Question 7

What are the steps for preparing dry copper sulphate crystals?

Answer 7

1. ) Heat sulphuric acid gently to increase rate of reaction with base.
2. ) Add copper oxide to sulphuric acid, stirring after each addition.
   3) Add copper oxide to sulphuric acid in excess to ensure that all the acid has reacted. insoluble,solid copper oxide will sink to the bottom.
3. ) Filter to remove unreacted, insoluble copper oxide.
4. ) Pour filtrate (salt solution) into an evaporating basin.
5. ) Pour water into beaker and heat on bunsen burner with evaporating dish on top.
6. ) Heat water gently (don’t bring to boil) to evaporate water from copper sulphate solution
7. ) When two thirds of the solution is evaporated, place the evaporating basin out on the windowsilll.