Thank you to Coleen McKellar, Biology and General Science Teacher, Crocus Plains Regional Secondary School, Brandon, Manitoba for sharing this resource she has developed.
1. Before you added the colour changing reagent, did you think the two unfiltered samples had the same amount of iron?
2. Did you change your mind about this after adding the reagent?
3. Why do you think it is important for this experiment that these two samples have the same iron concentration?
4. Before you added the colour changing reagent how different did the filtered and the unfiltered raw water samples look?
5. How different did the filtered and unfiltered bio-oxidized samples look?
6. Which of the two filtered samples appeared to have the most iron in it?
7. Was this confirmed by the iron test?
8. Which sample filtered better?
9. Why do you think one sample filtered better than the others?