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Class 12 Chemistry Investigatory Project Work, Practical- Determination of Caffeine in Tea Samples

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King George's Medical University
King George's Medical University

Class 12 Chemistry Investigatory Project Work, Practical- Determination of Caffeine in Tea Samples Just edit the name in first and second page of this project and the project is all yours. Watch my video for further explaination https://www.youtube.com/watch?v=1IoOGG_SBzw&lc=z22ju3nxqvrvzrghz04t1aokgmmjnqr0ld5exqhxchswrk0h00410

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CHEMISTRY INVESTIGATORY PROJECT SESSION 2017-18 SESSION 2016-17 SUBMITTED BY: PRANSHU DIWAKAR XII A 12119 SUBMITTED TO: Ms. AMRIT KAUR MAM
CERTIFICATE This is to certify that the original and genuine research work is carried out to investigate about the subject matter and the related data collection and has been completed solely and satisfactorily by this student regarding the Project titled, Determination of Caffeine in Tea Samples Signature of
External Examiner Chemistry Teacher ACKNOWLEDGEMENT It gives me great pleasure to express my gratitude towards our chemistry teacher for her guidance, support and encouragement throughout the duration of the project. Without her motivation and help the successful completion of this project would not have been possible.
PRANSHU DIWAKAR (Name and signature of the student)
CONTENTS Introduction Theory a) Caffeine b) Uses of caffeine c) Effects of Caffeine Material Required Procedure Observations Result
Bibliography INTRODUCTION Tea is the most commonly and widely used soft beverage in the household. It acts as a stimulant for central nervous system and skeletal muscles. That is why tea removes fatigue, tiredness and headache. It is also used for lowering body temperature. The principal constituent of tea, which is responsible for all these properties, is the alkaloid-caffeine. The amount of caffeine in tea leavers varies from sample to sample. Pure caffeine has been found to be a tasteless substance. The xanthene beverages found in tea also create a medical problem. Often the physicians face the question whether to
deny caffeine-containing beverages to patients or not. In fact children are more susceptible than adults to excitation by xanthene. For this reason, tea and coffee should be excluded from their diet. It has a high tannin content may be as high as 50 mg per cup. After all our main stress is on the presence of caffeine in xanthene beverages and so in this project we will study and observe the quantity of caffeine varying in different samples of tea leaves.
Theory Caffeine The most important methylated alkaloid that occurs naturally is caffeine. Its molecular formula is C8H10N4O2. Its IUPAC name is 1, 3, 7-trimethylxanthene and common name is 1- ethylated thiobromine. Purely it is white, crystalline solid in the form of needles. Its melting point is 1230c.
It is the main active principle component of tea leaves. Uses of Caffeine In medicine, it is used to stimulate, central nervous system and to increase flow of urine. Because of its stimulating effects, caffeine has been used to relieve fatigue. But it is dangerous and one may collapse if not consumes it under certain limit. Caffeine is also used in analgesic tablets, as it is believed to be a pain reliever. It is also beneficial in migraines.
Effects of Caffeine It is psycho - stimulant. It improves physical and mental ability. Its effect in learning is doubtful but intellectual performance may improve where it has been used to reduce fatigue or boredom. When administered internally, it stimulates heart and nervous system and also acts as diuretic. On the contrary their excessive use is harmful to digestion and their long use leads to mental retardation.
Procedure First of all, 50 grams of tea leaves were taken as sample and 150 ml of water was added to it in a beaker. Then the beaker was heated up to extreme boiling. The solution was filtered and lead acetate was added to the filtrater, leading to the formation of a curdy brown coloured precipitate. We kept on adding lead acetate till no more precipitate has been formed. Again solution was filtered. Now the filtrate so obtained was heated until it had become 50 ml.
Then the solution left was allowed to cool. After that, 20 ml. of chloroform was added to it. Soon after, two layers appeared in the separating funnel. Now separate the lower layer. The solution then exposed to atmosphere in order to allow chloroform to get evaporated. The residue left behind was caffeine. Then we weighed it and recorded the observations. Similar procedure was performed with different samples of tea leaves and quantity of caffeine was observed in them.
OBSERVATION 1. Red Label Tea (Brooke Bond) Weight of china dish 46.60g s Weight of china dish 47.20gms. with precipitate Amount of caffeine 0.60gms 2. Yellow Label Tea (Lipton) Weight of china dish 46.60gms Weight of china dish 47.15gms. Amount of caffeine 0.55gms
3. Green Label Tea (Lipton) Weight of china dish 46.60gms. Weight of china dish 47.05gms. with precipitate Amount of caffeine 0.45g s. RESULTS:- Quantityofcaffeine Red label tea - 60mg. /sample of 50 gm. Yellow label tea - 55mg./sample of 50 gm. Green label tea - 45mg./sample of 50 gm.
Percentage ofcaffeine Red label tea 0.12% Yellow label tea 0.11% Green label tea 0.9%
Bibliography Wikipedia -the free encyclopedia https://www.caffeineinformer.com/caffeine-content/tea-brewed http://www.mayoclinic.org/healthy-lifestyle/nutrition-and- healthy-eating/in-depth/caffeine/art-20049372?pg=2 http://www.theteaspot.com/about-tea.html allaboutjiophone-org.webnode.com

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Class 12 Chemistry Investigatory Project Work, Practical- Determination of Caffeine in Tea Samples

  • 1. CHEMISTRY INVESTIGATORY PROJECT SESSION 2017-18 SESSION 2016-17 SUBMITTED BY: PRANSHU DIWAKAR XII A 12119 SUBMITTED TO: Ms. AMRIT KAUR MAM
  • 2. CERTIFICATE This is to certify that the original and genuine research work is carried out to investigate about the subject matter and the related data collection and has been completed solely and satisfactorily by this student regarding the Project titled, Determination of Caffeine in Tea Samples Signature of
  • 3. External Examiner Chemistry Teacher ACKNOWLEDGEMENT It gives me great pleasure to express my gratitude towards our chemistry teacher for her guidance, support and encouragement throughout the duration of the project. Without her motivation and help the successful completion of this project would not have been possible.
  • 4. PRANSHU DIWAKAR (Name and signature of the student)
  • 5. CONTENTS Introduction Theory a) Caffeine b) Uses of caffeine c) Effects of Caffeine Material Required Procedure Observations Result
  • 6. Bibliography INTRODUCTION Tea is the most commonly and widely used soft beverage in the household. It acts as a stimulant for central nervous system and skeletal muscles. That is why tea removes fatigue, tiredness and headache. It is also used for lowering body temperature. The principal constituent of tea, which is responsible for all these properties, is the alkaloid-caffeine. The amount of caffeine in tea leavers varies from sample to sample. Pure caffeine has been found to be a tasteless substance. The xanthene beverages found in tea also create a medical problem. Often the physicians face the question whether to
  • 7. deny caffeine-containing beverages to patients or not. In fact children are more susceptible than adults to excitation by xanthene. For this reason, tea and coffee should be excluded from their diet. It has a high tannin content may be as high as 50 mg per cup. After all our main stress is on the presence of caffeine in xanthene beverages and so in this project we will study and observe the quantity of caffeine varying in different samples of tea leaves.
  • 8. Theory Caffeine The most important methylated alkaloid that occurs naturally is caffeine. Its molecular formula is C8H10N4O2. Its IUPAC name is 1, 3, 7-trimethylxanthene and common name is 1- ethylated thiobromine. Purely it is white, crystalline solid in the form of needles. Its melting point is 1230c.
  • 9. It is the main active principle component of tea leaves. Uses of Caffeine In medicine, it is used to stimulate, central nervous system and to increase flow of urine. Because of its stimulating effects, caffeine has been used to relieve fatigue. But it is dangerous and one may collapse if not consumes it under certain limit. Caffeine is also used in analgesic tablets, as it is believed to be a pain reliever. It is also beneficial in migraines.
  • 10. Effects of Caffeine It is psycho - stimulant. It improves physical and mental ability. Its effect in learning is doubtful but intellectual performance may improve where it has been used to reduce fatigue or boredom. When administered internally, it stimulates heart and nervous system and also acts as diuretic. On the contrary their excessive use is harmful to digestion and their long use leads to mental retardation.
  • 11. Procedure First of all, 50 grams of tea leaves were taken as sample and 150 ml of water was added to it in a beaker. Then the beaker was heated up to extreme boiling. The solution was filtered and lead acetate was added to the filtrater, leading to the formation of a curdy brown coloured precipitate. We kept on adding lead acetate till no more precipitate has been formed. Again solution was filtered. Now the filtrate so obtained was heated until it had become 50 ml.
  • 12. Then the solution left was allowed to cool. After that, 20 ml. of chloroform was added to it. Soon after, two layers appeared in the separating funnel. Now separate the lower layer. The solution then exposed to atmosphere in order to allow chloroform to get evaporated. The residue left behind was caffeine. Then we weighed it and recorded the observations. Similar procedure was performed with different samples of tea leaves and quantity of caffeine was observed in them.
  • 13. OBSERVATION 1. Red Label Tea (Brooke Bond) Weight of china dish 46.60g s Weight of china dish 47.20gms. with precipitate Amount of caffeine 0.60gms 2. Yellow Label Tea (Lipton) Weight of china dish 46.60gms Weight of china dish 47.15gms. Amount of caffeine 0.55gms
  • 14. 3. Green Label Tea (Lipton) Weight of china dish 46.60gms. Weight of china dish 47.05gms. with precipitate Amount of caffeine 0.45g s. RESULTS:- Quantityofcaffeine Red label tea - 60mg. /sample of 50 gm. Yellow label tea - 55mg./sample of 50 gm. Green label tea - 45mg./sample of 50 gm.
  • 15. Percentage ofcaffeine Red label tea 0.12% Yellow label tea 0.11% Green label tea 0.9%
  • 16. Bibliography Wikipedia -the free encyclopedia https://www.caffeineinformer.com/caffeine-content/tea-brewed http://www.mayoclinic.org/healthy-lifestyle/nutrition-and- healthy-eating/in-depth/caffeine/art-20049372?pg=2 http://www.theteaspot.com/about-tea.html allaboutjiophone-org.webnode.com