pre lab quiz 4
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Caffeine is an
Alkaloi Nitrogen containing compound which is typically an Organic base
Caffeine forms what in acidic solution
Water soluble salt
Caffeine forms water soluble salt in
Acidic solution
It is known to be a natural stimulant and can be found in various beverages such as coffee, tea and soft drinks
Caffeine
Caffeine increase… , reduce… and increase their capacity of
Alertness Drowsiness Thinking
What are the other constituents found in tea leaves
Pigments Cellulose Chlorophylls Tannins
In aq solution, it will form
Conjugates acid salt of caffeine
An acidic aq solution will form conjugated acid salt of caffeine which will increase
Its water solubility
In what solution do caffeine becomes neutral and has a fair solubility in water
Basic solutions
In basic solution, caffeine bcms…
Neutral
What is weakly acidic
Tannins
Tannins is weakly acidic that can be converted to
Water soluble salts
Caffeine can be extracted from the aq solution using
Dichloromethane or chloroform
Caffeine can be extracted from… using dichloromethane or chloroform
Aq solution
What are extracted tgt with caffeine may be neglected
Small amt of organic impurities
Small amt of organic impurities that are extracted tgt with caffeine may be
Neglected
The low volatility of dichloromethane and chlororform allows…
Drying easily
What allows drying easily of dichloromethane and chlororform
The low volatility
Materials needed
10teabags of same brand (not decaffeinated) Cheesecloth/ handkerchief Scissors
Reagents:
Anhydrous sodium carbonate (Na2CO3) Dicholoromethane (CH2Cl2) Iodine crystals or 15% sulfuric acid in ethanol Methanol
Instrruments:
Electric stove
Glassware and apparatus:
2 beaker 600ml 2 beaker 250ml 2 stirring rod Graduated cylinder 100ml Beaker 100ml Sepratory funnel 250ml Graduated cylinder 10ml Water trough Stainless water bath Thermometer
weigh how many grams of sodium carbonate then transfer it to where
17.5g 250ml
add how much water in the sodium carbonate
125ml