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Organic Chemistry LAB > Experiment#4: Isolation of Caffeine from Dried Tea Leaves > Flashcards

Experiment#4: Isolation of Caffeine from Dried Tea Leaves Flashcards

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1
Q

A basic alkaloid from the Methylxanthine family. [1,3,7 - trimethylxanthine]

A

Caffeine

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2
Q

In this compund’s pure form, it is odorless, white and fleecy.

A

Caffeine

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3
Q

CAFFEINE
Caffeine is an alkaloid from what family exactly?

A

Methylxanthine

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4
Q

CAFFEINE
Caffeine has the _____ ___ system, a framework that plays an important role in living systems.

A

Purine Ring System

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5
Q

CAFFEINE
Caffeine is odorless, has a bitter taste and is ___ ____ in water.

A

highly soluble

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6
Q

CAFFEINE
Medications designed to increase the amount of water and salt expelled from the body as urine. Caffeine acts as one of these.

A

Diuretics

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7
Q

CAFFEINE
The stimulation of the heart resulting in a relaxation of the blood vessels.

A

Vasodilation

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8
Q

CAFFEINE
A) Small doses of Caffeine (50-200 mg) and b) high doses of Caffeine (over 200 mg) result in what sort of effects on the human body?

A

A) Small doses can increase alertness and reduce drowsiness and fatigue.
B) Large doses can result in ”coffee nerves” (insomnia, restlesness, headaches and muscle tremors)

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9
Q

COMPOSITION OF TEA LEAVES
The principal structural material of all plant cells. Tea leaves are primarily made up of this.

A

Cellulose

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10
Q

COMPOSITION OF TEA LEAVES
Cellulose is insoluble in water, and thus can be separated from caffeine by…?

A

Hot Water Extraction

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11
Q

TYPES OF TEA
This type of tea is produced through complete fermentation.

A

Black Tea

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12
Q

TYPES OF TEA
Catechins, which make up 20% of black tea’s dry weight, is oxidized during fermentation to form _________ and ___________.

A

Theaflavins and Thearubigins

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13
Q

TYPES OF TEA
These contribute to the sensory characteristic bright orange-red color of black tea.

A

Theaflavins

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14
Q

COMPOSITION OF TEA LEAVES
Basic nitrogen containing compounds found in plants.

A

Alkaloids

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15
Q

TYPES OF TEA
These leaves for this tea are heated immediately after harvesting, mechanically wound and compressed, and then dried to ensure the preservation of color.

A

Green Tea

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16
Q

COMPOSITION OF TEA LEAVES
Astringent, bitter plant polyphenols that either bind and precipitate or shrink proteins that have acidic behavior.

A

Tannins

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17
Q

COMPOSITION OF TEA LEAVES
Colored polyphenolic compounds of high molecular weight that thave acidic behavior and are water-soluble complex substances.

A

Tannins

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18
Q

COMPOSITION OF TEA LEAVES
As much as __% by weight of the leaf material in tea plants consists of caffeine.

A

5%

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19
Q

TYPES OF TEA
Also known as silver needle tea, this type of tea is a slightly-fermented type of tea.

A

White Tea

20
Q

TRUE or FALSE | COMPOSITION OF TEA LEAVES
Chlorogenic Acids are water soluble and have acidic properties.

A

TRUE

21
Q

TRUE or FALSE | COMPOSITION OF TEA LEAVES
Plant fats are soluble due to them having large hydrophilic groups present in their molecular structure.

A

FALSE. Plant fats are insoluble because they have large hydrophobic groups.

22
Q

The body’s secondary source of energy (the first being glucose). This contains a high percentage of saturated fatty acids.

A

Triacylglycerol [TAGS]

23
Q

COMPOSITION OF TEA LEAVES
Any type of colored substance produced by a plant.

A

Plant Pigments

24
Q

COMPOSITION OF TEA LEAVES
Based on the Schematic Procedure during the post-lab discussion, provide the 4 possible Insoluble Cellular Materials present in tea leaves.

A
  • Cellulose
  • Fats
  • Plant Pigments
  • Proteins
25
Q

COMPOSITION OF TEA LEAVES
These are esters formed between caffeic and quinic acids, representing an abundant group of plant polyphenols in the human diet.

A

Chlorogenic Acids

26
Q

COMPOSITION OF TEA LEAVES
A group of phenolic secondary metabolites produced by certain plant species and an important component of coffee.

A

Chlorogenic Acids

27
Q

COMPOSITION OF TEA LEAVES
Biochemical substances that are insoluble in water and are soluble in nonpolar solvents.

A

Plant Fats (Lipids)

28
Q

Used to refer to lipids that are solid at room temperature.

A

Fats

29
Q

COMPOSITION OF TEA LEAVES
Chlorophylls, carotenoids and flavonoids are examples of what?

A

Plant Pigments

30
Q

PROCESS OF EXTRACTION
Provide the 7 characteristics of a Good Solvent for Liquid-Liquid Extraction.

A
  • Low Boiling Point
  • Does not react with solute or other solvent
  • Not toxic
  • Not highly flammable
  • Immiscible with water
  • Inexpensive
  • Readily dissolves caffeine at room temperature
31
Q

PROCESS OF EXTRACTION
This extraction process allows soluble components to be removed from solids using a solvent.

A

Solid-Liquid Extraction

32
Q

PROCESS OF EXTRACTION
Based on the pdf lecture, what are the 2 possible applications of Solid-Liquid Extraction?

A
  • Obtaining oil from oil seeds
  • Leeching of metal salts from ores
33
Q

PROCESS OF EXTRACTION
What are the 2 components of tea leaves that are readily soluble in hot water and are separated from the tea leaves themselves during Solid-Liquid Extraction?

A

Caffeine and Tannins

34
Q

PROCESS OF EXTRACTION
An extraction that used a liquid solvent to remove a liquid component from a liquid mixture.

A

Liquid-liquid Extraction

35
Q

PROCESS OF EXTRACTION
This extraction is also known as partitioning.

A

Liquid-liquid Extraction

36
Q

PROCESS OF EXTRACTION
Provide at least 2 applications of Liquid-Liquid extraction out of the 4 provided in the lecture.

A
  • Removal of vitamins from aqueous solutions
  • Removal of aromatic compounds from crude oil fractions
  • In the chemical and mining industries
  • Downstream recovery of fermentation products
37
Q

TRUE or FALSE | PROCESS OF EXTRACTION
In Liquid-Liquid Extraction, the aqueous layer will always be at the top and the organic layer will always be at the bottom.

A

FALSE. The determination of which solvent is at the top or bottom depends on the respective liquids’ densities.

38
Q

TRUE or FALSE | PROCESS OF EXTRACTION
Dichloromethane is denser than water, meaning this organic layer will be found at the top.

A

FALSE. Denser liquids will always be found at the bottom.

39
Q

PROCESS OF EXTRACTION
The ratio of the concentration of a compound in the two phases of a mixture of two immiscible solvents at equilibrium; dependent on temperature.

A

Distribution Coefficient

40
Q

PROCESS OF EXTRACTION
______ ______ is a drying agent, and will remove any water that may still be present in the mixture.

A

Sodium Sulfate

41
Q

PROCESS OF EXTRACTION
Sodium sulfate, calcium chloride and magnesium sulfate are all examples of…?

A

Anhydrous Salts

42
Q

PROCESS OF EXTRACTION
These have a high affinity for water and reverses back to its hydrous form after it has absorbed water.

A

Anhydrous Salts

43
Q

PROCESS OF EXTRACTION
Crude caffeine can be purified by _________.

A

Sublimation

44
Q

PROCESS OF EXTRACTION
Liquid-liquid Extraction is comprised of 2 steps, namely?

A
  • Mixing Phase
  • Phase Separation
45
Q

A procedure by which two liquids with different boiling points can be separated.

A

Distillation

46
Q

PROCESS OF DISTILLATION
Distillation is a powerful technique for separating the component substance from a miscible fluid mixture by means of selective ________ and ________.

A

Selective Evaporation and Condensation

Organic Chemistry LAB (10 decks)

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