Wednesday, April 9, 2008 - 4B

Went over graphs from Fractional Distillation Day 1 highlighting plateaus showing boiling points of alcohol and of water.

For the boiling point plateau for alcohol, students got between 79-83 deg C and for water, between 98-104 deg C. We chose swap out temperatures to be 84 deg C, 96 deg C.

In the first test tube, we should have pure alcohol. In the second, late alcohol and early water, and in the third, pure water.

Student did the Fractional Distillation Lab - Day 2 in which they performed the separation based on the different boiling points and swapping test tubes. I gave each student 25 ml of green liquid in their large test tube after they had put in 3-5 boiling chips.

While waiting for the swap out temperatures, students looked at their crystals from last time and sketched a diagnostic crystal for the salt.

Students shut down the alcohol lamp when they had 1 - 1.5 cm left in the "burning" (original large) test tube.

While waiting for equipment to cool, they performed a flammability test on the liquids in each test tube. The alcohol lamp is to the left and a coffee can 1/3 filled with water to the right. You dip the flammability strip into the liquid, hold it level in the flame, check for flammability, and then move your hand to the right to drop the strip into the can of water.

The lab went well, almost all lab groups managed to get to test tube 3.

Students made sure they had picture of lab set up, material list, procedure, and sketch of the graph in their notebooks.

Collected lab notebooks.