chapter 7 extraction and isolation Flashcards
what group of compounds does caffeine belong to
xanthines
separatory funnel upper portion is
organic
separatory funnel lower portion is
aqueous
what is the physical property would explain why one layer is on top of the other layer?
density
what is the purpose of adding sodium carbonate to the tea extraction?
to ensure that the acidic substance remains water soluble and caffeine will be present as the free base.
tea leaves contains
taninns (very acidic), number of colored compounds, small amount of undecomposed chlorophyll
Basic N in caffeine can be used to
increase and decrease water solubility
Acidic condition will form conjugate acid salt giving caffeine
increase water solubility as cation
what does vasodilator means
relaxes blood vessels
what does diuretic means
increases urination
used commercially to extract caffeine form coffee
organic solvent, methylene chloride, ethyl aceteate and supercritical carbon dioxide
in order to maximize extract from one solvent to nother, the difference in solubility must be
maximize
what does xanthine means?
it comes from plants, oldest known stimulants
if too much drying agent is added to the extract what is the overall effect on the final product?
it will absorb all the compound and lead to loss of products.
how will you identify the two layers experimentally?
The organic layer is typically less dense and will float on top of the aqueous layer. Add a small amount of water to the portion taken from the top layer (organic) and mix gently. If the liquid becomes cloudy or separates into two layers again, it indicates that it is the organic layer. If the liquid remains clear and homogeneous, it is likely the aqueous layer.
