Teacher’s Notes:

I use the following materials to make the unknown solutions:

Corn starch, albumin or egg white, glucose/dextrose To create a 1% solution, add 1g of your substance to 100 mL of

water. You can heat the water slightly to help dissolve the solids, if need be, but do not bring to a boil (especially the egg white)! Test your stock solutions to make sure you are able to observe a positive color change. If not, you may need to up the concentration of the solution.

All solutions except egg white will keep just fine in the fridge, but I would remind students to stir them before use in case the solute settles out of the solution.

Suggested solutions & expected results:A. Glucose (+ Benedicts reagent, blue to rusty orange or “puke” green)B. Corn starch (+ Iodine solution, amber to inky black)C. Albumin and glucose (+ Biuret reagent, blue to violet and + Benedicts

reagent, blue to rusty orange or “puke” green)D. Albumin (+Biurets reagent, blue to violet)E. “Control” distilled or tap water (- all reagents)

In the shortened version on the lab, just have three solutions and “D” would be the control/water.