chem lab 3 spring sem

Lab-3 Freezing Point Depression Part A. Confirming the Nature of Colligative Properties Solute Formula Grams Used Moles of Particles Initial Temp Final Temp Molality Urea CH 4 N 2 O 1.8097g 0.03 mol 4 ℃ -3 ℃ 0.41mol/kg Glucose C 6 H 12 O 6 5.4039g 0.03mol 1 ℃ -3 ℃ 0.41mol/kg. Sodium chloride NaCl 0.9053 0.015mol 2 ℃ -4 ℃ 0.20mol/kg 1. What conclusions can you draw by comparing the freezing points of the solutions of urea and glucose? Explain. - By comparing the freezing points of the solutions of urea and glucose we can conclude that urea and glucose have the same freezing point even though they began at different temperatures. 2. What conclusions can you draw by comparing the freezing points of the solutions of urea and sodium chloride? Explain. - After comparing the freezing points of the solutions of urea and sodium chloride we can conclude that sodium chloride has a lower freezing point than urea by 1 ℃ . Part B. Determining the Cooling Curve for Pure Cyclohexane Mass of cyclohexane used (in grams): 9.6546g Mass of cyclohexane used (in kilograms): 0.0096546kg The freezing point of cyclohexane (from the curve): 0 ℃ Attach a copy of your cooling curve.

Part C. Determining the K f for Cyclohexane Mass of naphthalene (in grams): 0.3065g Moles of naphthalene:2.3* 10−3mol Freezing point (from your curve): -2.9 ℃ Attach a graph of your cooling curve