1. Change in mass of vitamin C
Syougo Hujita Ryouko Tanaka Rina Miyagoshi

2. motives reduce the amount of vitamin C Wow! Really!?
The passage of time and temperature
reduce the amount of vitamin C
Wow! Really!?

3. Want to make good use
of our study in effective
ingestion of vitamin C.

4. The result
Hypothesis ?
Find a new law

5. Used reagent
Ascorbic acid solution (Ｌ‐C₆Ｈ₈Ｏ₆) (0.003mol/L)→… g/100ml
Aqueous solution of potassium iodide(K Ｉ)(0.1mol/L)→…1.6601g/100ml
Aqueous solution of potassium iodate(ＫＩＯ₃) (0.001mol/L)…0.0214g/100ml
Aqueous solution of metaphosphoric acid(ＨＰＯ₃) (２％)…0.8g/40ml　
Aqueous starch solution(１％)…0.4g/40ml　

6. experiment（１）method①
Put 10ml of ascorbic acid aqueous solution (L-C₆H₈O₆) into a conical beaker. 　　　　　　　　　　↓
Using a graduated grass, add 10ml of the aqueous solution of metaphosphoric acid (HPO₃) 10ml and 5ml of potassium iodide solution (KI). 　　　　　　　　　　↓
Using a Komagome pipette, add 2ml of starch solution . 　　　　　　　　　　↓
　　　　　　　I call it a beaker ①.

7. experiment（１）method②
Using burette to taking potassium iodate (KIO₃), and poured into a beaker ① little by little until the color change ↓
Once you become the contents are completely blue-violet of the beaker ①, the amount of reduced potassium iodate

8. The result of experiment
An expected result was not over first and the second.
Set point of Potassium iodate aqueous solution ・・・ １０ｍｌ

9. Consideration for Experiment1
Needless of use of heated starch solution .
Needless of use of ascorbic acid solution which we kept at the same time after we made it.

10. The result of Experiment 2

11. Procedure of Experiment2
1Prepare three kinds of ascorbic acid solution; one kept in a refrigerator, another kept at normal temperature and the other kept at fifty degrees centigrade. 2Measured the mass of vitamins C in each solution in the same way as experiment1.
A machine which keeps 50 degrees centigrade.

12. Considerations for Experiment 2
Consider vitamin C has the property that is vulnerable to heat.
Consider a decrement of vitamin C has a limit.

13. Future prospects
Check the mass of vitamin C following the changes in heat and times.
Consider if there is a law between vitamin C, heat and time.

14. Thank you for listening!