1. Problem №10 «pH Indicator»
Speaker:Artem Fursov
Team Russia

2. The problem
The juice of many fruits or vegetable crops contains a natural pH indicator that changes colors according to the acidity or basicity of the solution. Investigate such pH indicator juices and their mixes. Propose the most precise and effective composition and compare its properties with those of common indicator paper.

3. Goals: To analyze some juice for indicator
To make standard solution with conventional pH
To make analogy of litmus paper
To analyze indicator mechanism of work in terms of anthocyanin

4. Choice of juice
Make aqueous migrate from red cabbage, beet, pomegranate and red onion
Analyze aqueous migrate for indicator

5. Analyze juice for change color in different values of pH

6. Change color
Change color

7. Select of juice
We select a red cabbage for indicator because we can repeatability results and we can determined visually results.
Red cabbage has anthocyanin, which can change color.

8. Make a standard solution with conventional pH
For our experiment we make solution series of acid and alkali with conventional stage of pH is 1

9. The final stage
Put aqueous migrate from red cabbage in out solution with pH in diapason from 0 to 14 and watch color change of solution

10. Factors which effect to color
Quantity of conjugate bonds
Chromophores
-NR3, -CN,- NO2
Auxochromes
—ОН, —SH, NH2, C6H5O—

12. Our indicator scale is equal for litmus scale

13. Conclusions:
In experiment we make analogy of litmus paper from juice of red cabbage
We explore indicator mechanism of work in terms of anthocyanin

14. Thank you for your attention