rest

• How is copper purified

  • throigh electrolysis
• describe the purification of copper

  • the cathode is the pure sheet
  • the abode is impure sheet
  • positive cu2+ ions in the solution move to the cathode to get oxidaised (cu2+ + 2e- = cu) to make the pure sheet of copper bigger
  • at the anode impure is oxidised and cu2+ ions go into the solution and as one copper ion foes into the cathode another one is deposited into the solution so concentration stays the same
  • lump of sludge is at the bottom
• if a metal reacts with sulfuruic acid why does the reaction stop despite there being metal remaining

  • metal sulfate acts coats the metal acting as a barrier
  • prevents further contamination with the metal
• Balance equation between dilute sufluric acid and sodium hydroxide

  h2s04 + 2naoh = Na2so4 + h20
• How are pure dry crystals gathered

  • heat solution
  • warm place to dry
  • filter crystals
• Why is expected yield higher than theoretical

  • not all the water had been dried off properly
• what would u seen when copper carbonate powder is added to a beaker of sulfuric acid

  • fizzing blue solution
• what would u seen when a reaction is finished

  • no fizzing
  • no colour change
• Why does a new mixture evaporated rather than orginal mixture to in a titration to produce a pure sample

  • the orginal mixture contains a universal indicator
  • second mixture has no indicator so salt isnt contaminated