Determining Molar Mass by Freezing Point Depression

A.P. ChemistryDetermining Molar Mass by Freezing Point DepressionProcedure1. Put on your lab apron and goggles.2. Weigh out 10 g of solid lauric acid.Determination of the melting point of pure lauric acid.3. Place the lauric acid in to the test tube.4. Fill 600 mL beaker about ¾ full with tap water.5. Place beaker with water on hot plate and start heating water.6. Place test tube in beaker and heat until the lauric acid is completely melted(be sure to stir the lauric acid carefully with the thermometer)7. Once the lauric acid is completely melted, carefully remove the lauric acidfrom the hot water and allow it to cool. Keep the beaker of water warm forlater trials.8. Record the temperature every 30 seconds until the temperature reachesapproximately 35°C.Determination of the freezing point of lauric acid/benzoic acid mixture9. Weigh out 10 g of solid lauric acid.10. Place the lauric acid in to the test tube.11. Weigh out 1.0 g of benzoic acid and place into the test tube with the lauricacid.12. Using the hot water from the trial with pure lauric acid.13. Place test tube in beaker and heat until the lauric acid/benzoic acid mixture iscompletely melted (be sure to stir the lauric acid carefully with thethermometer)14. Once the mixture is completely melted, carefully remove it from the hotwater and allow it to cool.15. Record the temperature every 30 seconds until the temperature reachesapproximately 25°C.16. Repeat steps 9 through 15 two more times increasing the amount benzoic acidby 1.0 g each time.