Chem 2510: Organic Chemistry Lab
Prelim #1
What are the phases of TLC? - Answer 1. Stationary phase
2. Mobile phase
stationary phase - Answer the absorbent in a thin layer (silica, TLC, SiO2) and the absorbent is
adhered to a solid support (plastic/glass)
Mobile Phase - Answer fluid/solvent which flows through absorbent via capillary action
How to assess purity of a substance - Answer 1. Visualization
2. MP analysis
TLC - Answer valuable technique for separation and identification of a mixture of organic
compounds
retention factor - Answer report results of a TLC and compare results across time
the more polar, the ____ the Rf - Answer smaller
Rf of a substance can be adjusted by adjusting the relative polarity of a solvent system - Answer
More polar substances will travel farther than less polar substances
column chromatography - Answer Chromatography in which the substances to be separated
are introduced onto the top of a column packed with silica, pass through the column at different
rates that depend on the affinity of each substance for the adsorbent and for the solvent or
solvent mixture, and are usually collected in solution as they pass from the column at different
times
heterogeneous catalyst - Answer Has a different physical state to the substance being reacted.
Allows for removal of catalyst via filtration (reusable)
Recrystallization - Answer purification method that relies on Ksp and differential sollubilities of
contaminants and target compound and or relatively pure starting material
partition coefficient - Answer ratio of concentration of a compound in a mixture of 2
immiscible (or nearly) solvents at equilibrium
Prelim #1
What are the phases of TLC? - Answer 1. Stationary phase
2. Mobile phase
stationary phase - Answer the absorbent in a thin layer (silica, TLC, SiO2) and the absorbent is
adhered to a solid support (plastic/glass)
Mobile Phase - Answer fluid/solvent which flows through absorbent via capillary action
How to assess purity of a substance - Answer 1. Visualization
2. MP analysis
TLC - Answer valuable technique for separation and identification of a mixture of organic
compounds
retention factor - Answer report results of a TLC and compare results across time
the more polar, the ____ the Rf - Answer smaller
Rf of a substance can be adjusted by adjusting the relative polarity of a solvent system - Answer
More polar substances will travel farther than less polar substances
column chromatography - Answer Chromatography in which the substances to be separated
are introduced onto the top of a column packed with silica, pass through the column at different
rates that depend on the affinity of each substance for the adsorbent and for the solvent or
solvent mixture, and are usually collected in solution as they pass from the column at different
times
heterogeneous catalyst - Answer Has a different physical state to the substance being reacted.
Allows for removal of catalyst via filtration (reusable)
Recrystallization - Answer purification method that relies on Ksp and differential sollubilities of
contaminants and target compound and or relatively pure starting material
partition coefficient - Answer ratio of concentration of a compound in a mixture of 2
immiscible (or nearly) solvents at equilibrium
