Salt and Sand Mixture Lab Notes

Objective

• Separate a heterogeneous mixture of salt and sand.
• Determine the percentage of salt and sand in the mixture.

Materials Used

• Evaporating dish
• Wash cloth
• Balance for weighing
• Beaker
• Filter paper
• Funnel
• Erlenmeyer flask
• Bunsen burner
• Water

Procedure Overview

1. Initial Measurements

   • Mass of empty evaporating dish and watch glass: 80.67 g.
   • Mass of salt and sand mixture: 88.39 g.

2. Dissolving the Salt

   • Add about 10 mL of water to the salt and sand mixture.
   • Salt dissolves in water; sand does not.

3. Filtration

   • Set up filtration apparatus with funnel and Erlenmeyer flask.
   • Fold filter paper to create a filter.
   • Pour salt water through the filter, capturing sand.
   • Wash the sand with an additional 10 mL of water to ensure all salt is dissolved.
   • Observe that the sand is retained in the filter, while the salt water passes through to the beaker.

4. Separating Salt from Water

   • Pour the salt water into the evaporating dish.
   • Cover with a watch glass and heat over a Bunsen burner.
   • Water will evaporate due to its low boiling point, leaving salt behind.
   • Wait until all water evaporates.

5. Final Measurement

   • Final mass of the evaporating dish with salt: 83.69 g.

Calculations

• Mass of Salt: 83.69 g (final mass) - 80.67 g (mass of dish) = 3.02 g
• Mass of Sand: 88.39 g (initial mass) - 3.02 g (mass of salt) = 85.37 g
• Calculate percentage of salt and sand:
  • Percentage of Salt = (3.02 g / 88.39 g) * 100
  • Percentage of Sand = (85.37 g / 88.39 g) * 100

Key Concepts

• Heterogeneous Mixture: Mixture where components can be easily distinguished.
• Physical Properties Used for Separation:
  • Solubility: Salt dissolves in water; sand does not.
  • Boiling Point: Water evaporates at a lower temperature than salt.

Conclusion

• The separation of salt and sand was accomplished using differences in physical properties: solubility and boiling point.