Thursday, February 26, 2009

Thursday, Feb 26, 2009 - 4B

Reminded students to write up lab as they go and not leave it all for the end.
By today, they should have written up the Cover Sheet, General Statement, Day 1 Material List, Procedure, Diagram, and Safety Procedures.

Talked about Day 2 of Lab.
Drew diagram of apparatus and explained procedure and safety precautions.
You stop when you have 1-1.5 cm left in original test tube.
When done, compare the two liquids and then mix them back together to see if you get back the original.

Safety:
1. Put 3-5 boiling chips in test tube before you start heating to regulate the boiling and prevent burps
2. Closely monitor to prevent overboiling. You can move the wire gauze to increase or decrease the heat.
3. Make sure the rubber tubing in the collection test tube is above the level of the collected liquid (so liquid is not sucked back up if the heat decreases) but below the level of the water in the Erlenmeyer Flask (to allow for condensation)
4. Do not fill the Erlenmeyer Flask up so high that you spill water into the collection test tube.

For homework, students are to work on Day 2 material list, procedures, diagram, and safety.

Also went over flow chart and explained how to construct it.

Students started another run of Day 1 at about 2 pm and finished by 2:30 pm.

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