Purpose: Students select an IV and determine a DV to measure the affect of a relevant factor on diffusion rate. 

Criteria:  D, DCP, CE [Note: This is the first D-DCP-CE report assessed sumatively.]

Length:   3 hours (max)

Date (time): October 11-15, 2010

Cohort: 2012 exams

Objective:

Design and carry out an experiment to investigate a factor that affects the rate of diffusion. 

[Note: as first IB lab, I gave students three basic lab outlines for them to choose from: 

1. use agar and measure diffusion out of agar;
2. use dialysis tubing;
3. use vegetable of uniform consistency, like potato. 

We discussed several methods in class and students mixed and matched to produce their own unique experiment.  Most students designed and carrried out an independent design.

Students were pointed to "Tiger text" & p7-9 and Billiet's "Core Practicals" & internet to find basic methods that could be modified.

Student were provided an agar recipe for those who wanted to work with agar.