Title: pH Rainbow Tube
Question:How can you measure the acidity using the pH rainbow tube?
Purpose:
The purpose of us doing this experiment is to create a pH rainbow tube, where after we will figure out how to apply it into a rea- world situation.
Materials:
-Test tubes, large 20x150 mm
-Test tube rack
-Beral-type pipet,
-Hydrochloric acid solution, 0.1M ,20mL
-Sodium carbonate, saturated, 6mL
-Universal indicator, 3mL
Procedure:
1.Add about 3 mL of universal indicator solution and 20 mL of hydrochloric acid solution to a large test tube. Swirl the test tube to mix. This should produce a bright red color.
2. Fill a Beral-type pipet with sodium carbonate solution. (This is approximately 3 mL)
3. Tilt the test tube slightly and slowly squeeze the sodium carbonate solution down the side of the test tube to the bottom. The sodium carbonate solution will sink to the bottom of the test tube. Refill the pipet with more sodium carbonate and add to the test tube in the same way. (Total amount of sodium carbonate added is 6 mL)
4.Place the test tube on the test tube rack and observe the changes.
5. Colored layers form gradually resulting in a rainbow spectrum of colored layers in the tube that will remain for several days if left undisturbed.
6. Relate the colors to the reactions taking place in the test tube and the resulting changes in pH. Discuss your observations, inferences, explanations and extensions.
Safety Regulations:
Dilute hydrochloric acid and saturated sodium carbonate solutions are skin and eye irritants. Avoid contact of all chemicals with eyes and skin. Universal indicator solution is alcohol-based and is therefore inflammable. Keep away from flames and other ignition sources. Wear chemical splash goggles, chemical-resistant gloves, and a chemical-resistant apron. Review current Material Safety Data Sheets for additional safety, handling, and disposal information. Dispose of materials correctly.
Analysis and conclusion, also application and extension are not able to complete yet as part of the investigation, given the fact that the experiment has not been performed.