This document describes an experimental activity on chromatography of food dyes for a level five science class. The activity involves students using filter paper to separate mixtures of food dyes through elution with a salt water solution. The teacher's tasks are to introduce the activity, demonstrate how to spot the dyes on filter paper, and help students analyze the results. Students are asked to observe how the salt water causes the dyes to spread and note any separation of color components. They then answer questions about the process and components separated. The activity aims to demonstrate chromatography and separation of mixtures into pure substances or multiple parts.

1. CHARLINE PINET FONTENIAUD
MY PROJECT
TEACHING PRESENTATION
2012-2013 EFTIS_M1 ENGLISH FOR SCIENCE TEACHERS

2. EXPERIMENTAL ACTIVITY : CHROMATOGRAPHY
OF FOOD DYES.
1

3. EXPERIMENTAL ACTIVITY : CHROMATOGRAPHY
OF FOOD DYES.
 Level : five
1

4. EXPERIMENTAL ACTIVITY : CHROMATOGRAPHY
OF FOOD DYES.
 Level : five
 Part A of the program : homogeneous
mixtures and pure substances.
1

5. EXPERIMENTAL ACTIVITY : CHROMATOGRAPHY
OF FOOD DYES.
 Level : five
 Part A of the program : homogeneous
mixtures and pure substances.
 Skills and knowledge practiced
1

6. INTRODUCTION
2

7. INTRODUCTION
 Chromatography
2

8. INTRODUCTION
 Chromatography
2

9. INTRODUCTION
 Chromatography
2

10. INTRODUCTION
 Chromatography
2

11. INTRODUCTION
 Chromatography
 Equipment
2

12. INTRODUCTION
 Chromatography
 Equipment
2

13. INTRODUCTION
 Chromatography
 Equipment
2

14. INTRODUCTION
 Chromatography
 Equipment
2

15. INTRODUCTION
 Chromatography
 Equipment
2

16. INTRODUCTION
 Chromatography
 Equipment
2

17. CONDUCTING THE ACTIVITY
Time Teacher’s tasks Students’ tasks
Distribute the document to the students, introduce
5 min Read the document.
the activity.
Present the material, help the students depositing Prepare the filter paper and begin elution (by
10 min
drops of dye on the filter paper. placing the filter paper in salt water).
Pass among groups to give the main rule of Observe salt water "rises" in the filter paper, all
10 min
chromatography : do not move the beaker! note observations.
Help students exploit the chromatogram and Place filter paper in a stove, answer questions
15 min
answer questions. from the sheet.
3

18. CONDUCTING THE ACTIVITY
Time Teacher’s tasks Students’ tasks
Distribute the document to the students, introduce
5 min Read the document.
the activity.
Present the material, help the students depositing Prepare the filter paper and begin elution (by
10 min
drops of dye on the filter paper. placing the filter paper in salt water).
Pass among groups to give the main rule of Observe salt water "rises" in the filter paper, all
10 min
chromatography : do not move the beaker! note observations.
Help students exploit the chromatogram and Place filter paper in a stove, answer questions
15 min
answer questions. from the sheet.
40 min
3

19. CONDUCTING THE ACTIVITY
Time Teacher’s tasks Students’ tasks
Distribute the document to the students, introduce
5 min Read the document.
the activity.
Present the material, help the students depositing Prepare the filter paper and begin elution (by
10 min
drops of dye on the filter paper. placing the filter paper in salt water).
Pass among groups to give the main rule of Observe salt water "rises" in the filter paper, all
10 min
chromatography : do not move the beaker! note observations.
Help students exploit the chromatogram and Place filter paper in a stove, answer questions
15 min
answer questions. from the sheet.
40 min
3

20. SHEET
FOR
STUDENTS
4

21. SHEET
FOR
STUDENTS
 Experiment
4

22. SHEET
FOR
STUDENTS
 Experiment
 Questions
4

23. ANSWERS
5

24. ANSWERS
 What happens between the salt water and the
filter paper?
5

25. ANSWERS
 What happens between the salt water and the
filter paper?
 The water rises along the filter paper causing the dye
to spread
5

26. ANSWERS
 What happens between the salt water and the
filter paper?
 The water rises along the filter paper causing the dye
to spread
 Have you separated the components during this
experiment? Explain, naming the separated
components.
5

27. ANSWERS
 What happens between the salt water and the
filter paper?
 The water rises along the filter paper causing the dye
to spread
 Have you separated the components during this
experiment? Explain, naming the separated
components.
 Only the green dye is separated into
two distinct tasks of colours :
yellow and blue
5

28. ANSWERS
 What happens between the salt water and the
filter paper?
 The water rises along the filter paper causing the dye
to spread
 Have you separated the components during this
experiment? Explain, naming the separated
components.
 Only the green dye is separated into
two distinct tasks of colours :
yellow and blue
 The green dye is not a pure substance
5

29. CONCLUSION: KEY WORDS
6

30. CONCLUSION: KEY WORDS
« chromatography »
6

31. CONCLUSION: KEY WORDS
« chromatography »
« separate components »
6

32. CONCLUSION: KEY WORDS
« chromatography »
« separate components »
« homogeneous mixture »
6

33. CONCLUSION: KEY WORDS
« chromatography »
« separate components »
« homogeneous mixture »
« eluent »
6

34. CONCLUSION: KEY WORDS
« chromatography »
« separate components »
« homogeneous mixture »
« eluent »
« pure substance »
6

35. CONCLUSION: KEY WORDS
« chromatography »
« separate components »
« homogeneous mixture »
« eluent »
« pure substance »
« several parts »
6

36. THANK YOU FOR YOUR ATTENTION
7
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