Hypothesis: By measuring the pH of the unknown and known chemicals, the types of chemicals in the unknown bottles will become known.
Purpose: The purpose of this experiment is to determine the type of chemicals that are inside the mislabeled bottles.
Materials:
• pH strips
• 8 bottles of known chemicals: o silver nitrate o iron (III) nitrate o copper (II) nitrate o sodium iodine o sodium hydroxide o nitric acid o lead (II) nitrate o sodium carbonate
• 8 bottles of unlabeled chemicals the same contents as known chemicals
• 1 well tray
Procedure
1. Place 7-10 drops of each chemical (known and unknown) into separate wells in the well tray.
2. Observe the different colors of the chemicals and record the colors that are similar.
3. Place a pH strip in each well and let it sit for 30 seconds.
4. Match the color to the corresponding color of the strip to the pH chart on the container.
5. Record the results of the pH of both the known and unknown chemicals in a table.
6. Match the pH of the unknown chemicals to the known chemicals. More than 2 chemicals with the same pH are to be set aside.
7. Rinse wells with soap and water.
8. …show more content…
This experiment was adding one drop of water to each of four solutions. This only diluted the chemical and did not generate any useful results. Another error was the bottle of chemical t, which was lead (II) nitrate. In the first experiment, these two chemicals had a pH that differed by 4, more than any of the other chemicals. This problem could have been due to a mistake in dilution when the chemical was being bottled, or it was outdated. Furthermore, there are two types of lead nitrate, so the bottles may have been mixed up in the chemical room. Finally, the pH strips could have lead to potential error. For this lab, the pH strips were effective. However, in the future, there could be error in reading them or the color bleeding on the