Contamination Lab OBJECTIVE: TLW determining the meaning of collected data and its relevance to the question being investigated and compare experimental results of peers and construct a reasoned argument to justify conclusions while utilizing science safety procedures and investigating the effects of cross contamination BACKGROUND: Give an example how contamination has affected your life. Explain your example and how it might have been prevented. LABORATORY MATERIALS: Safety glasses, test tube, unknown solution, dropper/pipet, phenolphthalein, 3 M NaOH solution, test tube rack, distilled water PROCEDURES: 1) Each student will obtain a numbered test tube. Write down your unknown number in your lab book and make observations on the unknown sample. 2) Using a pipet, the student will carefully trade about 10 drops of solution with 8 people. While trading solutions, the student should keep an accurate record of who they traded with and in what order they traded. 3) After trading solutions, 3 – 4 drops of phenolphthalein is added to each sample by the teacher. 4) Additional observations are made on the solution.