RP8 - Water Purification

• What is the aim of water purification?

  Analysis and purification of water samples
• What are the main components of the water purification process?

  • pH measurement
  • Removal of dissolved solids
  • Distillation
• What equipment is needed for pH tests?

  Safety goggles and universal indicator
• What type of water samples are used for pH measurement?

  Samples of water at different pH values
• What is required to test for dissolved solids?

  Sample of prepared salt solution or mineral water
• What equipment is used for the distillation process?

  Conical flask with delivery tube and bung
• What is the method for analyzing a sample of water?

  1. Test pH with universal indicator
  2. Weigh empty evaporating basin
  3. Evaporate 10 cm³ water
  4. Reweigh basin after cooling
  5. Calculate mass of dissolved solids
• How do you calculate the mass of dissolved solids in water?

  Change in mass of evaporating basin
• What are the steps for purifying water by distillation?

  1. Place water in conical flask
  2. Heat water gently until boiling
  3. Collect 1 cm depth of distilled water
  4. Analyze with cobalt chloride paper
• What should you do after collecting distilled water?

  Analyze with cobalt chloride paper
• What is a safety precaution during water purification?

  Do not ingest the water
• What is the purpose of cobalt chloride paper in distillation?

  • To analyze the distilled water
  • Indicates presence of water vapor