Materials:

• Food coloring stock bottle set
• Spectrophotometer or light table
• Set of colored filters
• Test tubes & test tube rack
• Graduated cylinder
• Eye dropper
• Unknown [record # on unknown please]
• Water & paper towels

This is it. this is all you need to solve the problem. No other materials are available.

Reports:

1. as accurately as you can, what is the concentration of the unknown?
2. how did you get there? List all of the steps and reasonings. Why did you choose the dilutions that you used? could you have used a different series?
3. you may talk amoung yourselves and other groups. this is not a competition.
4. into how much water would one have to dilute one drop of concentrated dye from the stock bottle to get the dilution of their unknown?
5. how dilute a solution is it possible to mix and still detect above the blank? with and without the colored filter?