Chemical and biological theories come to life in this natural continuation to the study of Osmosis and Diffusion (LAB-22). In this activity, students use a colloidal solution of starch and sodium chloride to vividly observe dialysis. They also observe diffusion of a solute through a semi-permeable membrane. Students then remove an inorganic salt from a colloid and test for the presence of chloride ions and starch with simple color tests. Individualized worksheets guide students through the step-by-step procedure in this self-directed lab activity.
Scientific Concepts:
Observe diffusion of a solute through a semi-permeable membrane
Remove an inorganic salt from a colloid
Test for presence of chloride ions and starch with simple color tests
Content List:
1Teacher's Guide with MSDS
30Student Worksheets and Guides
12Chemplates‚®
30Containers, plastic
3Droppers
30Dialysis membranes
3Iodine Solution, bottle
2Sodium Chloride, bottle
2Starch Suspension, bottle
1Deionized Water, bottle
1Silver Nitrate, bottle
Classroom Planning:
To complete this kit requires 1 ~50-minute class period