Activity 6 - Extraction Of Caffeine From Tea

Question 1

Molecular formula of caffeine

Answer 1

C8H10N4O2

Question 2

Other names of caffeine

Answer 2

1. Guaranine
2. Methyltheobromine
3. 1,3,7-Trimethylxanthine
4. Theine

Question 3

IUPAC name of caffeine

Answer 3

1,3,7-Trimethylpurine-2,6-dione

Question 4

Density of caffeine

Answer 4

1.23 g/cm3

Question 5

Boiling point of caffeine

Answer 5

178*C

Question 6

Melting point of caffeine

Answer 6

235*C

Question 7

Taste of caffeine

Answer 7

Bitter

Question 8

Odor of caffeine

Answer 8

Odorless

Question 9

Biological action of caffeine

Answer 9

1. Cardiac stimulation
2. Respiratory stimulation
3. Diuretic effect

Question 10

Classification of caffeine

Answer 10

CNS stimulant

Question 11

Uses of caffeine

Answer 11

1. Mild CNS stimulant

2. Headache, in combination of ergotamine tartrate

Question 12

Color of DCM

Answer 12

Colorless

Question 13

Melting point of DCM

Answer 13

96.7*C

Question 14

Boiling point of DCM

Answer 14

39.6*C

Question 15

Density of DCM

Answer 15

1.3266 g/cm3

Question 16

Molecular formula of DCM

Answer 16

CH2Cl2

Question 17

Other names of dichloromethane

Answer 17

1. DCM
2. Methylene chloride
3. Methylene dichloride
4. Solmethine
5. Narkotil
6. Solaesthin

Question 18

Uses of dichloromethane

Answer 18

1. As a paint stripper and a degreaser
2. In foods, used to decaffeinate coffee and tea as well as to prepare extracts of hops and other flavorings.
3. As an aerosol spray propellant
4. As a blowing agent for polyurethane foams

Question 19

Color of sodium sulfate

Answer 19

White

Question 20

Odor of sodium sulfate

Answer 20

Odorless

Question 21

Melting point of sodium sulfate

Answer 21

32.38*C

Question 22

Boiling point of sodium sulfate

Answer 22

1.429*C

Question 23

Density of sodium sulfate

Answer 23

2.664 g/cm3

Question 24

Solubility of sodium sulfate in ethanol

Answer 24

Insoluble

Question 25

Solubility of sodium sulfate in glycerol and hydrogen iodide

Answer 25

Soluble

Question 26

Molecular formula of sodium sulfate

Answer 26

Na2SO4

Question 27

Other names of sodium sulfate

Answer 27

1. Sulfuric acid disodium salt 2. Glauber's salt 3. Disodium sulfate 4. Thenardite 5. Sol mirabilis 6. Mirabilite

Question 28

Uses of sodium sulfate

Answer 28

1. Manufacture of detergents 2. Used in kraft process of paper pulping 3. Orally, an effective saline laxative

Question 29

Color of sodium carbonate

Answer 29

White

Question 30

Odor of sodium carbonate

Answer 30

Odorless

Question 31

Taste of sodium carbonate

Answer 31

Strong alkaline taste

Question 32

Melting point of sodium carbonate

Answer 32

34*C

Question 33

Density of sodium carbonate

Answer 33

2.54 g/cm3

Question 34

Solubility of sodium carbonate in alcohol

Answer 34

Insoluble

Question 35

Molecular formula of sodium carbonate

Answer 35

Na2CO3

Question 36

Other names of sodium carbonate

Answer 36

1. Washing soda 2. Soda ash 3. Soda crystals 4. Disodium carbonate

Question 37

Uses of sodium carbonate

Answer 37

1. Used in the manufacture of glass 2. Used as a strong base 3. Used as a pharmaceutical aid used as an alkalizing agent 4. Used as a water softener and helps laundry detergents to lather more effectively, particularly when the water in which the laundry is being washed is hard. 5. Used as an additive swimming pools to neutralize the corrosive effects of chlorine and raise the pH 6. Used as a primary standard for acid-base titrations because it is solid and air stable, making it easy to weigh accurately.

Question 38

White crystalline powder or glistening needles

Answer 38

Caffeine

Question 39

1 gram of caffeine dissolves in _________ of water

Answer 39

50 ml

Question 40

1 gram of caffeine dissolves in __________ water at 80*C

Answer 40

6 ml

Question 41

1 gram of caffeine dissolves in __________ alcohol

Answer 41

75 ml

Question 42

1 gram of caffeine dissolves in __________ alcohol at 60*C

Answer 42

25 ml

Question 43

1 gram of caffeine dissolves in __________ chloroform

Answer 43

6 ml

Question 44

1 gram of caffeine dissolves in __________ ether

Answer 44

600 ml

Question 45

Caffeine is a naturally occurring __________ derivative.

Answer 45

Xanthine

Question 46

Due to the structural similarity to __________, caffeine binds to and blocks __________ receptors, thereby preventing the inhibitory effects of __________ on nerve cells.

Answer 46

Adenosine

Question 47

Caffeine leads to stimulation of medullary, vagal, vasomotor, and respiratory centers in the brain; and the release of __________.

Answer 47

Epinephrine

Question 48

Other substances found in tea leaves:

Answer 48

1. Cellulose | 2. Tannins

Question 49

Toxic dose of caffeine for adults

Answer 49

5-10 g

Question 50

Toxic dose of caffeine for children

Answer 50

3 g

Question 51

Solvent used in extraction of caffeine

Answer 51

Dichloromethane

Question 52

Colorless liquid (volatile)

Answer 52

Dichloromethane

Question 53

Odor of dichloromethane

Answer 53

Sweet aroma

Question 54

Miscibility of dichloromethane with water

Answer 54

Immiscible

Question 55

Miscibility of dichloromethane in acetate, alcohol, benzene, ether, CHCl3

Answer 55

Miscible

Question 56

Natural sources of dichloromethane

Answer 56

1. Volcanoes 2. Oceanic sources 3. Macro-algae

Question 57

Drying agent used in extraction of caffeine

Answer 57

Sodium sulfate

Question 58

White crystalline solid

Answer 58

Sodium sulfate

Question 59

1 gram of sodium sulfate dissolves in __________ water

Answer 59

1.5 ml

Question 60

White powder (hygroscopic)

Answer 60

Sodium carbonate

Question 61

1 gram of sodium carbonate dissolves in __________ water

Answer 61

3 ml

Question 62

1 gram of sodium carbonate dissolves in __________ boiling water

Answer 62

1.8 ml