Salt and Sand Mixture Lab Notes

Overview

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

Materials Used

• Evaporating dish
• Watch glass
• Scale (for measuring mass)
• Beaker
• Filter paper
• Bunsen burner
• Water

Procedure Steps

1. Initial Measurements

   • Measure the mass of the empty evaporating dish and watch glass:
     • Mass (empty): 80.67 g
   • Measure the mass of the salt and sand mixture:
     • Mass (mixture): 88.39 g

2. Dissolving Salt

   • Add the salt and sand mixture to a small beaker.
   • Add approximately 10 mL of water.
   • Key Concept: Salt dissolves in water, while sand does not.

3. Filtration Process

   • Set up filtration apparatus (Erlenmeyer flask and funnel).
   • Fold filter paper to create a filter.
   • Pour the saltwater through the filter:
     • Sand remains on top of the filter paper.
     • Collect the saltwater in the flask below.
   • Wash the sand with another 10 mL of water to collect any remaining salt.
   • Note: Filtration may take time due to small holes in the filter paper.

4. Separating Salt from Water

   • Transfer the saltwater to the evaporating dish.
   • Cover with watch glass.
   • Heat over the Bunsen burner until all water evaporates.
   • Key Concept: Different boiling points allow separation; water evaporates first.

5. Final Measurements

   • After evaporation, measure the mass of the evaporating dish and salt:
     • Final Mass (salt + dish): 83.69 g
   • Calculate the mass of the salt by subtracting the mass of the empty dish.

Calculations

• To find the mass of salt:
  • Mass of salt = Final mass - Mass of empty dish
• To find the percentage of salt and sand in the mixture:
  • Percentage of salt = (Mass of salt / Total mass of mixture) x 100
  • Percentage of sand = (Mass of sand / Total mass of mixture) x 100

Conclusion

• The lab demonstrates the use of differences in physical properties (solubility and boiling point) to separate components of a mixture.