Universal Indicator

1. Aim: why did we do the experiment?

to make acid-base indicators using everyday substances.

1. Equipment: what did you use for your experiment?

1. Red cabbage

2. Beetroot

3. Tea

4. Tumeric

5. Cranberry juice

6. A beaker

7. Water

8. Bunsen burner

9. Gauze mat

10. Pipette

1. Method: what steps did you complete to get your results for your experiment?  Use slide 100 to help

Cabbage and beetroot

1. Chop up into small pieces until you have enough to fill 2 cups
2. Place cabbage in large beaker and add water to cover the cabbage
3. boil over Bunsen burner for at least 10 minutes for the colour to leach out of the cabbage
4. filter out plant material to obtain the colour. the liquid is about pH 7 (the exact pH colour will depend on the pH of the water)
5. repeat this for beetroot

for tea

1. put 100ml of water into a beaker and boil
2. turn off Bunsen burner and put in 3 tea bags in beaker
3. remove tea bags when tea is very strong
4. place in small beaker and leave to 1 side

for cranberry juice

1. pour into beaker and leave to 1 side

for tumeric

1. mix 1 teaspoon of tumeric in 100ml cup of alcohol

place in small beaker and leave to 1 side

Results: Pictures 

1. Discussion: starting discussion questions (you can include more detail)
   • What colour did each indicator change in an acid vs. a base? Use your results table to help with this
   • Cabbage turned red when mixed with acid and green when mixed with base
   • Were some indicators better than others – if so, why do you think this is?
   • yes because it changed the colour and was more useful/helpful

 

1. Conclusion: starting conclusion questions (you can include more detail)
   • did all your experiments work – if they didn’t, why? 
   • yes they did
   • What could you do to improve next time?
   • take more time and do it where there is more space