In today’s blog post I will be posting a blog about how we experimented by making acid-base indicators using everyday substance and seeing the results when mixed with acid.
Aim: Our Aim for this experiment was to see how our homemade acid-base indicator reacts with acid and base.
Equipment: The equipment needed for this experiment are the following: Red cabbage, tea, beetroot, turmeric, cranberry juice, a beaker, water, tripod, Bunsen burner, gauze mat, 1. mol L-1 HCI and 1. mol L-1 NaOH.
Instructions: Once you have gotten all the equipment needed for the experiment you would need to follow the following instruction to procced with the experiment to make acid-basic indicator(This is for cabbage and beetroot):
1. Chop the cabbage into small pieces until you have enough to fill 2 cups.
2.Place the cabbage in a large beaker and add water to cover the cabbage.
3. Boil over a Bunsen burner for at least ten minutes for the color to leach out of the cabbage.
4.Filter out the plant material to obtain a red-purple-bluish colored liquid. This liquid is at about pH 7. (The exact color you get depends on the pH of the water.)
5.Place in small beaker and leave it to one side.
6. Repeat this method for the beetroot.
To make an acid-base indicator out of tea the steps are instructed below:
1.Put 100ml of water into a beaker and boil.
2.Turn off the Bunsen Buner and put in three tea bags in the beaker.
3.Remove the tea bags when the tea is very strong.
4.Place in a small beaker and leave to one side.
To make an acid-base indicator out of cranberry juice the steps are instructed below:
1.Pour into a beaker and leave to one side.
(NOTE: We never used Turmeric) To make an acid-base indicator out of Turmeric the steps are instructed down below:
1.Mix 1 teaspoon of Turmeric in 100ml cup of alcohol.
2.Place into a small beaker and leave to one side.
Next steps: After making an acid-base indicator you can now try mixing it with acids and base, below is an image on how we did the experiment and what were the results:
Results for each indicator here:
| Indicator | Colour in HCl (acid) | Colour in NaOH (base) |
| Cabbage (group 1 and 2) | Pink | Green |
| Beetroot (group 3 and 4) | Red | Yellow |
| Cranberry juice (group 5) | Yellow | Dark yellow/Brown |
| Tea (group 5) | peach/light red | Brown |
Image shown below of our experiment:
Discussions:
- What color did each indicator change in an acid vs. a base? Cabbage’s color when mixed with acid was Pink and when mixed in with base the color was Green. Beetroot’s color when mixed with acid was red and when mixed with base was yellow. Cranberry’s color when mixed with acid was yellow and when mixed with base the color was dark yellow. Tea’s color when mixed with acid was light red and when mixed with base was brown.
- Why did indicators change color? The indicators changed colors due to them reacting with acid and base.
- Were some indicators better than others – if so, why do you think this is? I don’t think so.
Conclusion:
- did all your experiments work – if they didn’t, why? I don’t think it worked due to the reason that the colors that appeared doesn’t fit on the pH scale therefore doesn’t seem like it was working which proves the point that the acid-base indicator didn’t do so well or that we had made a mistake(Most Likely).
- What could you do to improve your science next time? What I could do to improve my science next time is to make sure that our experiment went smoothly and that none of our group members are goofing/playing around.
- How could you make your results more reliable? (think about human error) What we could do to make our results more reliable is by checking multiple times and having our team members verify and agree that we are clear to go to the next step.
This is all for my blog, Thank you for having a look at my blog bye.