Practical:Making Soluble Salts"

• What is the main topic of the video from free science lessons?

  How to make a soluble salt using an acid
• Why is making a soluble salt a required practical?

  It is highly likely that there will be a specific question on this in the exam
• What is an example of a soluble salt mentioned in the video?

  Copper sulfate
• What do all salts contain?

  A positive ion and a negative ion
• What is the positive ion in copper sulfate?

  The metal ion Cu$^{2+}$
• From where can the metal ion in a salt 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
• What is the negative ion in copper sulfate?

  The sulfate ion SO$_{4}^{2-}$
• What acid is used to make copper sulfate?

  Sulfuric acid
• What are the two types of reactants mentioned for making soluble salts?

  Metal oxides and metal carbonates
• What is the first step in making 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 the acid?

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

  The copper oxide reacts and seems to disappear
• What color does the solution turn when copper sulfate is formed?

  Blue
• What should you do if the solution remains clear blue after adding copper oxide?

  Stop adding copper oxide
• What is done to remove unreacted copper oxide from the solution?

  Filter it away using a filter funnel and filter paper
• What is the final step to make crystals of copper sulfate?

  Evaporate the solution
• How should the copper sulfate solution be heated during evaporation?

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

  24 hours
• What should be done to the copper sulfate crystals after they form?

  Scrape them on a paper towel and gently pat them dry
• What is the end product of the procedure described in the video?

  Pure dry crystals of copper sulfate
• What are the steps involved in making pure crystals of a soluble salt like copper sulfate?

  1. Start with dilute sulfuric acid.
  2. Gently heat the acid.
  3. Add copper oxide and stir until the solution turns blue.
  4. Filter out unreacted copper oxide.
  5. Evaporate the solution to form crystals.
  6. Leave for 24 hours and dry the crystals.
• What equipment is needed to filter the unreacted copper oxide?

  • Filter funnel
  • Filter paper
• What is the significance of ensuring no acid remains at the end of the reaction?

  • Prevents contamination of the salt
  • Ensures complete reaction
• What color indicates the presence of copper sulfate in the solution?

  • Blue color indicates copper sulfate