WATER PURIFICATION REQUIRED PRACTICAL

• What is the difference between potable water and pure water?

  Potable water is safe to drink but may contain dissolved solids, while pure water contains no dissolved solids.
• What is the pH of pure water?

  7
• Why might potable water not have a pH of 7?

  Because it may contain dissolved acids or alkalis.
• What is the first step to check if a water sample is pure?


  Check the pH of the water sample.
• How can you check the pH of water?


  By placing a small amount of the water onto a piece of universal indicator paper.
• What does it indicate if the pH of the water sample is not 7?

  The water sample contains dissolved acid or alkali and is therefore not pure.
• What happens to the mass of the evaporating basin if the water sample contains dissolved solids?

  The mass of the empty evaporating basin will increase due to the formation of crystals from the dissolved solids.
• What should you do after filling the evaporating basin with the water sample?

  Place it on a tripod with gauze and gently heat it with a Bunsen burner.
• If the mass of the evaporating basin does not increase after evaporation, what can be concluded?

  The water did not contain any dissolved solids and could be pure.
• What is not investigated in this required practical regarding water purity?

  The presence of dissolved gases in the water sample.
• What is the method used to purify water by distillation?

  Heating the water to create vapor, which then condenses back into liquid water.
• What equipment is used in the distillation process described?

  A conical flask, delivery tube, test tube, and a beaker with ice and water.
• What occurs when the water vapor enters the cold test tube during distillation?

  It condenses back into liquid water.
• What is the characteristic of distilled water?

  It contains no dissolved solids and has a pH of 7.
• What are the steps to analyze a sample of water for purity?

  1. Check the pH using universal indicator paper.
  2. Weigh an empty evaporating basin and record its mass.
  3. Fill the basin with the water sample and heat until evaporated.
  4. Weigh the basin again to check for dissolved solids.
• What is the process of purifying water by distillation?

  1. Heat the water sample in a conical flask.
  2. Water evaporates and forms vapor (steam).
  3. Vapor travels through a delivery tube to a cold test tube.
  4. Vapor condenses back into liquid water in the test tube.
  5. The result is distilled water, which is pure.