heating in a crucible

• method for heating in a crucible?

  1. weigh dry and clean crucible and lid
  2. add 2grams of compound and heat using a bunsen burner for a couple of minutes
  3. let it cool
  4. reweigh crucible and lid
  5. heat again until a constant mass is reached this mens the reaction is complete
• why do we use a lid?

  improves accuracy as no solids will be loss but make sure its loose to allow gases to escape
• why dont we use a larger sample of compound?

  the decomposition in unlikely to be complete
• why dont we use smaller samples of the compound?

  the percentage uncertainty will be too high
• why does the crucible need to be dry?

  you will get inaccurate results as mass loss will be to high due
• draw the apparatus 


  crucible