Required Practical 8

Aim

To analyse and purify water samples from different sources, including pH, dissolved solids and distillation.

Materials Needed

• Water samples from different sources, such as tap water, river water, well water, and rainwater.
• pH test strips or pH metre.
• Conductivity metre or TDS metre (Total Dissolved Solids metre).
• Distillation apparatus (including a distillation flask, condenser, and receiving flask).
• Heat source (Bunsen burner or electric heater).
• Thermometer.
• Glass beakers or containers.
• Funnel and filter paper (or a filter flask if available).
• Safety goggles and lab coat.

Safety Precautions

• Wear safety goggles and a lab coat to protect against accidental spills or splashes.
• Do not ingest any water samples, and handle all equipment with care.

Procedure

1. pH Analysis:
   1. Take small samples of water from each source and pour them into separate clean and labelled containers.
   2. Dip a pH test strip into each water sample or use a pH metre to measure the pH of each sample.
   3. Record the pH values of each water sample.
2. Measurement of Dissolved Solids:
   1. Rinse the conductivity or TDS metre probe with distilled water before each measurement.
   2. Immerse the probe in each water sample and wait for the reading to stabilise.
   3. Record the conductivity or TDS values of each water sample.
3. Distillation:
   1. Set up the distillation apparatus as per the manufacturer's instructions.
   2. Pour a larger sample of the water from each source into the distillation flask.
   3. Heat the distillation flask gradually using a Bunsen burner or electric heater.
   4. Collect the distilled water in the receiving flask.
   5. Measure the temperature of the distilled water using a thermometer.
   6. Record the temperature when the first drop of distilled water is collected and when the temperature starts to rise again.
4. Purification:
   1. After distillation, compare the pH and TDS values of the original water samples with those of the distilled water.
   2. Note any changes in pH and TDS levels after the purification process.
   3. Discuss the effectiveness of distillation in removing dissolved solids and impurities from the water samples.
5. Conclusion:
   1. Analyse the data obtained from pH testing, TDS measurements, and distillation.
   2. Compare the water quality of each source based on the results.
   3. Discuss the importance of water purification methods in ensuring safe and clean drinking water.