chem souble salts

• What positive ion is present in copper sulfate?

  The metal ion is cu$^{2+}$
• From where can the metal ion in copper sulfate come?

  From the metal itself, metal oxide, metal hydroxide, or metal carbonate
• Why can't copper sulfate be made by reacting copper with dilute sulfuric acid?

  Because copper is not reactive enough for that reaction
• What are the four sources of the metal ion in copper sulfate?

  Metal itself, metal oxide, metal hydroxide, metal carbonate
• What negative ion is present in copper sulfate?

  The sulfate ion is $SO_4^{2-}$
• What acid is used to make copper sulfate?

  Sulfuric acid
• What is the first step in making pure crystals of a soluble salt?

  Start with a fixed amount of dilute sulfuric acid
• Why is dilute sulfuric acid considered the limiting reactant?

  Because it will run out during the reaction
• What should be avoided when heating dilute sulfuric acid?

  Boiling the acid
• What happens when copper oxide is added to dilute sulfuric acid?

  The copper oxide reacts and the solution turns blue
• When should you stop adding copper oxide to the acid?

  When the solution is clear blue and no more copper oxide dissolves
• What is done to remove unreacted copper oxide from the solution?

  Filter it away using a filter funnel and filter paper
• What is the next step after filtering the solution to remove unreacted copper oxide?

  Evaporate the copper sulfate solution
• How is the copper sulfate solution heated during evaporation?

  Gently over a beaker of boiling water
• How long should the solution be left to form copper sulfate crystals?

  24 hours
• What should be done after the copper sulfate crystals have formed?

  Scrape them on a paper towel and gently pat them dry
• What are the steps involved in making pure crystals of a soluble salt like copper sulfate?

  1. Start with dilute sulfuric acid.
  2. Add copper oxide and stir until the solution turns blue.
  3. Filter out unreacted copper oxide.
  4. Evaporate the solution until half remains.
  5. Leave to cool for 24 hours to form crystals.
  6. Scrape and dry the crystals.
• What are the key considerations when performing the practical to make a soluble salt?

  • Ensure all acid is reacted to avoid contamination.
  • Heat acid gently to prevent boiling.
  • Stop adding copper oxide when the solution is clear blue.
  • Filter out unreacted solids before evaporation.