1. Lab 4 Fractional Distillation Objective - To separate a mixture of two liquids by collecting vapors at their boiling point.

2. Experiment - Pour about 50 mL of mixture into a grad. cyl. Soak a paper strip in the mixture. Hold the paper over the burner to test for flammability. Record results

3. Heat mixture gradually and collect 2 fractions Time (min)Temp (°C) 0 0.5 1.0 1.5 …

4. OdorFlammability Mixture Fraction 1 Fraction 2 Fraction 3 (leftover in flask)

5. Analysis - 1. Construct a graph of temperature vs. time for the heating of the solution. Place the time along the horizontal and the temperature along the vertical axis. Only include the temperature range you recorded along the vertical for a more accurate graph. Label the graph. Results -

6. Questions - 1. Why is this method of separation called “fractional” distillation? 2. What would the flat line in your graph indicate? 3. Propanol is an compound that has a boiling point around 98 ̊ C. Explain why a mixture of propanol and water would be difficult to separate by fractional distillation.