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37 Cards in this Set
- Front
- Back
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________ are naturally occurring compounds. |
Alkaloids |
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Alkaloids are characterized by a basic nitrogen usually present in a _______. |
Heterocyclic ring |
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What are the different types of heterocyclic rings? |
Pyrrole Pyridine Pyrrolidine Quinoline Isoquinoline |
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The nitrogen in an alkaloid can also be present in an… |
Aliphatic side chain |
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Alkaloids are derivatives of… |
Ammonia |
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Being derivatives of ammonia, they occur mostly as ______ and occasionally as _______ amines |
Tertiary, secondary |
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They have wide applications in the field of… |
pharmacology, medicine, and toxicology |
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Alkaloids can occur as _____ of inorganic and organic plant acids in complex mixture with water-insoluble compounds. |
salts |
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Examples of water-insoluble compounds. |
Gum Proteins Mineral salts Tannins Lipids Resins |
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In tea leaves, the major alkaloid found is _______. |
Caffeine |
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Caffeine is a _______ and a _______, _______, and a _______ stimulant. |
diuretic and a cardiac, respiratory, and psychic stimulant |
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Caffeine is known to be soluble in _________. |
Hot water |
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Caffeine is considerably more soluble in _______ than in water. |
Dichloromethane |
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The solubility of caffeine in water can be enhanced by addition of... |
dilute strong acids |
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It is the ability of two or more substance to form a homogenous mixture spontaneously, without undergoing any chemical reaction. |
Solubility |
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What happens when a pure solid or liquid dissolve? |
The ions or molecules making it up get separated from each other, then become surrounded by solvent molecules. |
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The solubility behavior of a substance depends chiefly on their... |
polarity |
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What is the convenient rule of thumbs? |
"like dissolves like" |
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Ionic compounds tend to be more soluble in polar solvents because of... |
ion-dipole intercation |
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What are the two types of extraction? |
Solid-Liquid Extraction Solid-Solid Extraction |
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(Solid-Liquid Extraction) The desired substance is initially present as... |
part of a solid mixture. |
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(Solid-Liquid Extraction) The substance is separated from that mixture by... |
extracting it once or several times with an appropriate solvent, preferably one that is low-boiling. |
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(Solid-Liquid Extraction) The extracted material may be recovered by... |
evaporating and distilling off the solvent. |
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(Liquid-Liquid Extraction) When two liquids do not mix to form a solution, they are said to be... |
immiscible |
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(Liquid-Liquid Extraction) The mixture will have two layers, with the _______ liquid found a the bottom. |
denser |
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(Liquid-Liquid Extraction) When this mixture is shaken thoroughly, any solute initially present in either layer becomes _________ between the two immiscible layers. |
distributed |
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(Liquid-Liquid Extraction) A higher amount of solute goes into the layer in which it is more _______. |
soluble |
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(Liquid-Liquid Extraction) The concentration of a substance in each layer is given by the equation... |
C1/C2 = Kc |
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(Liquid-Liquid Extraction) The desired substance is in a liquid mixture and is obtained by... |
the preferential transfer to an extracting solvent in which the desired substance has a higher solubility |
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_______ is usually one of the liquids used in liquid-liquid extraction. |
water |
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The other liquid is usually a ________ or ________ that is immiscible with water. |
weakly polar or non polar organic solvent |
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How is liquid-liquid extraction accomplished? |
by shaking the liquid mixture with the extracting solvent in a separatory funnel. |
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________ breaks the organic solvent into small globules, thereby increasing the surface for contact f the organic and aqueous mixtures. |
shaking |
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After standing, the layers are separated by draining the lower layer through the... |
stem/stopcock |
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How to determine which of the two layers is the organic layer? |
A small portion of the bottom layer is allowed to drop on a watch glass containing water. |
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In using a separatory funnel, make sure that the stopcock is ______ before filling in the specified amount of any liquid. |
closed |
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What is done to plant extracts in order to determine the presence of certain metabolites ncluding alkaloids, saponins, and the like? |
phytochemical screening |
