OCHEM LAB FINAL EXAM QUESTIONS
WITH VERIFIED ANSWERS { GRADED
A+}
solubility - ✔✔like dissolves like
acetanilide is polar, therefore a polar solvent dissolves it
Steps for choosing a good solvent: - ✔✔1. The solvent should not chemically
react with your desired compound
2. the solvent should not dissolve your compound when it is cold and should
dissolve your compound when hot
3. The solvent should either dissolve impurities at all temperatures of not dissolve
the impurities at all
chromatography - ✔✔method for identification, isolation and purification; useful
for monitoring reactions
, stationary phase (polar) - ✔✔An adsorbant (eg. silica gel) is supported on a solid
back
mobile phase (nonpolar) - ✔✔A solvent mixture that carries your compound
across the stationary phase
The distance travelled.... - ✔✔depends on the polarity of the compound and the
polarity of the mobile phase (solvent)
If the mobile phase is too nonpolar, - ✔✔the compound won't travel
If the mobile phase is too polar, - ✔✔there will be too much movement
Retention factor - ✔✔distance spot traveled/distance solvent traveled
Infrared Spectroscopy - ✔✔An instrumentation method of analysis that identifies
bonds from absorption of the infrared radiation of different wavelengths
bond stretching: - ✔✔asymmetric or symmetric
Bond bending: - ✔✔twisting, wagging, rocking, or scissoring
spacial reasoning: - ✔✔the ability to generate, retain, retrieve, and transform
well-structured visual images
WITH VERIFIED ANSWERS { GRADED
A+}
solubility - ✔✔like dissolves like
acetanilide is polar, therefore a polar solvent dissolves it
Steps for choosing a good solvent: - ✔✔1. The solvent should not chemically
react with your desired compound
2. the solvent should not dissolve your compound when it is cold and should
dissolve your compound when hot
3. The solvent should either dissolve impurities at all temperatures of not dissolve
the impurities at all
chromatography - ✔✔method for identification, isolation and purification; useful
for monitoring reactions
, stationary phase (polar) - ✔✔An adsorbant (eg. silica gel) is supported on a solid
back
mobile phase (nonpolar) - ✔✔A solvent mixture that carries your compound
across the stationary phase
The distance travelled.... - ✔✔depends on the polarity of the compound and the
polarity of the mobile phase (solvent)
If the mobile phase is too nonpolar, - ✔✔the compound won't travel
If the mobile phase is too polar, - ✔✔there will be too much movement
Retention factor - ✔✔distance spot traveled/distance solvent traveled
Infrared Spectroscopy - ✔✔An instrumentation method of analysis that identifies
bonds from absorption of the infrared radiation of different wavelengths
bond stretching: - ✔✔asymmetric or symmetric
Bond bending: - ✔✔twisting, wagging, rocking, or scissoring
spacial reasoning: - ✔✔the ability to generate, retain, retrieve, and transform
well-structured visual images
