Required Practical 1:Making Soluble Salts

• What is the purpose of the practical described in the video?

  The purpose is to describe how to make a soluble salt using an acid.
• What is a salt and how is it formed?

  • A salt is formed from the reaction of an acid with a base.
  • It contains positive ions (metal ions) and negative ions (from the acid).
• What is the positive ion in copper sulfate?

  The positive ion is the copper ion, $Cu^{2+}.$
• From where can the metal ion in a salt come?

  • From the metal itself.
  • From a metal oxide.
  • From a metal hydroxide.
  • From a 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 to take place.
• What is the negative ion in copper sulfate?

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

  Sulfuric acid.
• What are the steps involved in making pure crystals of a soluble salt?

  1. React a metal oxide or carbonate with dilute sulfuric acid.
  2. Filter out unreacted solid.
  3. Evaporate the solution to form crystals.
  4. Dry the crystals.
• What is the first step in making the soluble salt?

  The first step is to start with a fixed amount of dilute sulfuric acid.
• Why is it important to ensure no acid remains at the end of the reaction?

  To prevent contamination of the salt.
• What should be done to the acid before adding the metal oxide?

  The acid should be gently heated until it's almost boiling.
• What happens to the copper oxide when it is added to the acid?

  The copper oxide reacts and seems to disappear, turning the solution blue.
• What indicates that the reaction between copper oxide and sulfuric acid has stopped?

  When the solution turns clear blue and some copper oxide powder remains.
• What is the purpose of filtering the solution after the reaction?

  • To remove unreacted copper oxide.
  • To ensure the solution contains only the soluble salt.
• What is the next step after filtering the solution?

  The next step is to evaporate the solution to form crystals.
• How is the evaporation process carried out?

  The solution is heated gently over a beaker of boiling water until about half remains.
• How long should the solution be left to form crystals?

  The solution should be left for 24 hours in a cool place.
• What is the final step in obtaining pure dry crystals of copper sulfate?

  The final step is to scrape the crystals onto a paper towel and gently pat them dry.