Making Salts RPA

Question 1

metal + acid –>

Answer 1

salt + hydrogen

Question 2

the practicle requires that we understand how to make salts from

Answer 2

metal oxides or metal carbonates

Question 3

what are limiting reactants?

Answer 3

reactants that will run out

Question 4

what is the limiting reactant in the making salts RPA?

Answer 4

acid

Question 5

what happens if there is any acid left at the end?

Answer 5

salt is contaminated

Question 6

what do we sometimes add excess base (alkali) when preparing a sample of salt crystals

Answer 6

to neutralise any left over acid and prevent the salt from being contaminated

Question 7

what are the steps to the making salts RPA?

Answer 7

1. add 5cm^3 of acid to a beaker
2. gently heat until almost boiling
3. add 5g of metal oxide/carbonate and stir
4. continue adding until metal oxide/carbonate powder remains after stirring, meaning all of the acid has reacted
5. filter insoluble excess metal oxide/carbonate
6. pour solution into a evaporating basin and gently heat in a water bath until roughly half of the solution evaporates
7. leave solution for 24 hours for salt crystals to form