Identifying Organic Compounds Lab Report

Purpose: To use indicators to test for the presence of organic compounds in certain substances.

Hypothesis: Honey will contain sugars, egg white contains proteins, corn oil contains lipids, oats contains starches and proteins, gelatin contains sugars and proteins, potatoes contain starch, and apple juice contains lipids and sugars.

Materials: 9 test tubes

Test tube rack

Test tube holder

Grease pencil

Hot plate

20 ml honey solution

20 ml egg white and water mixture

20 ml corn oil

Oats and water

20 ml gelatin and water solution

20 ml potato and water mixture

20 ml apple juice and water mixture

20 ml unknown substance #1

20 ml unknown substance #2

Paper towels

600 ml beaker

Brown paper

Biuret reagent

Benedict's solution

Iodine solution

Procedure: 1. Place test tubes in the test tube rack. Use the grease pencil to label each test tube based on the substance that will be placed in them.

2. To test for starches, fill each test tube with 5ml of the substance indicated by the label.

3. Add 5 drops of iodine solution to each test tube. The contents will change to a blue-black color in the presence of starch.

4. Record your observations.

5. Wash test tubes thoroughly.

6. To test for sugar, fill each test tube with 5ml of the substance indicated by the label. Add 10 drops of Benedict's solution to each test tube.

7. Fill the beaker half-way with water. Heat the water with the hot plate to a gentle boil.

8. Place tubes into beaker with the test tube holder and wait 5 minutes, then remove the test tubes with the test tube holder and place them back into the test tube rack.

9. Check for a change in color from blue to green, yellow, orange, or red in the presence of sugars.

10. Record your observations then wait for the test tubes to cool and wash them thoroughly.

10. To test for proteins, fill each test tube with 5ml of the substance indicated by the label. Add 5 drops of Biuret reagent to each test tube.

11. Gently shake the contents of each tube. Biuret reagent changes from blue to violet in the presence of proteins.

12. Record your observations then wash test tubes thoroughly.

13. To test for lipids, divide the piece of brown paper into 9 equal sections.

14. Write the name of one test substance in each section.

15. Rub a small amount of each substance onto its corresponding section.

16. Wait five minutes till dry.

17. Hold paper up to light. A translucent spot indicates the presence of lipids.