The Rainbow Tube Experiment
Learning objective: to observe how many pH colour bands are created using HCl and NaOH.
Material HCl (0.1 mol) Sodium Carbonate Na2CO3 (0.1 mol) Universal indicator | Apparatus 1 test tube 1 test tube rack 2 droppers Safety goggles |
Procedure:
- Use a dropper to fill ¾ of the test tube with HCl.
- Use another dropper to let 5 to 10 drops of Na2CO3 gently slide down the inner side of the test tube while slightly tilting the test tube.
- Straighten the test tube and observe what happens.
Questions:
1. How many color bands were produced?
we got 5 colour bands.
2. Compare your result with 3 other groups.
3. Predict the pH of the colour bands.
1, 2, 3, 5, and 11.
4. Using prior knowledge and experience, explain how the color bands were produced.
The colour band were produced by the universal indicator by adding sodium carbonate.
5. If other groups have different results, explain how you think this happened.
It might not be our problem because we've followed the instruction that the teacher told us. Or the other group added too much sodium carbonate into the test tube.
6. On a scale of 1 to 5, 5 being the best, rate your participation in this investigation and explain why.
4, because i accidentally shook the test tube nearly causing the rainbow to disappear.
7. On a scale of 1 to 5, 5 being the best, rate your other 1 group member’s participation in this investigation and explain why.
5, because she conducted me to do a perfect experiment.
8. How can you improve your investigation?
To improve the investigation we should be given a longer tube with a cap so that more colours can be formed and to prevent the substances from spilling
1. How many color bands were produced?
we got 5 colour bands.
2. Compare your result with 3 other groups.
3. Predict the pH of the colour bands.
1, 2, 3, 5, and 11.
4. Using prior knowledge and experience, explain how the color bands were produced.
The colour band were produced by the universal indicator by adding sodium carbonate.
5. If other groups have different results, explain how you think this happened.
It might not be our problem because we've followed the instruction that the teacher told us. Or the other group added too much sodium carbonate into the test tube.
6. On a scale of 1 to 5, 5 being the best, rate your participation in this investigation and explain why.
4, because i accidentally shook the test tube nearly causing the rainbow to disappear.
7. On a scale of 1 to 5, 5 being the best, rate your other 1 group member’s participation in this investigation and explain why.
5, because she conducted me to do a perfect experiment.
8. How can you improve your investigation?
To improve the investigation we should be given a longer tube with a cap so that more colours can be formed and to prevent the substances from spilling