What is an epoxide correct answers A three-membered ring that contains oxygen as one of the ring atoms. Lots of ring strain
What is the most common way turn an alkene into an epoxide? correct answers By treating it with a proxy acid (m-CPBA) However, this proxy acids are explosive and hard to ha...
CHEM 310 Exam 1 Meredith || Already Passed.
What is an epoxide correct answers A three-membered ring that contains oxygen as one of the
ring atoms. Lots of ring strain
What is the most common way turn an alkene into an epoxide? correct answers By treating it
with a proxy acid (m-CPBA) However, this proxy acids are explosive and hard to handle.
During the first portion of trans-stilbene experiment, what was the function of NBS? correct
answers NBS provided a bromide atom via bromohydration reaction, which created a
bromonium ion on the trans-stilbene
What is a permeator? Provide an example of a chemical we used in class. correct answers
DMSO, a chemical that can pass through protective dermal layers and into the body.
Can expose us to toxic effects of a specific permeator or act as a carrier for other toxic/hazardous
chemicals.
Example the process of performing an extraction in trans-stilbene experiment. correct answers 1)
Ice cold DI poured into sep funnel
2) Transfer the reaction mixture to the sep. funnel
3) Add ether to sep funnel.
In the trans-stilbene experiment, a bromohydrin will be purified by which method? correct
answers Via recrystallization from hexanes
During the creation of bromohydrin, in the trans-stilbene experiment, most of the DMSO was
removed from the product during which step? correct answers The extraction
Finding the melting points in the trans-stilbene experiment were crucial because they told us
what? correct answers They told us the stereochemistry of our product.
trans vs. cis
When solid anhydrous MgSO4 is added to liquid, what is its function? correct answers To
remove any microscopic droplets of water.
It is a drying agent.
Why is DMSO difficult to remove from reaction mixtures? In the trans-stilbene experiment, how
did we remove DMSO? correct answers DMSO has a very high boiling point, which is why we
removed it during our extraction process.
During recrystallization, what will happen if too much hot solvent is used to dissolve the crude
compound? correct answers Few or zero crystals will be isolated.
, Crystals form may remain contaminated.
What are the three requirements to make a proper melting point sample? correct answers 1)
Finely ground up solid
2) Compacted well into a capillary tube
3) sample should be about 2-3mm in height
What should you do if the baseline of your TLC plate dips below the level the solvent as you put
the pate into the developing chamber? correct answers Start over with a new TLC plate, dump
out this solvent, and put less in the beaker next time.
Only need a small layer of solvent
When should you mark the solvent front on your TLC plate? correct answers After you remove
the TLC plate from the developing chamber, but before the solvent evaporates
How many layers of liquid should you have during the purification via extraction? correct
answers Two layers: aqueous (bottom layer) and organic (top layer)
What are the sample that come out the bottom of a chromatography column called? correct
answers Fractions
If you perform two chemical reactions in sequence, what is the overall percent yield for
converting A to C?
A to B = 80% yield
B to C = 70% correct answers 0.8 * 0.7 * 100% = 56
Will the most polar or most non-polar compound come out of the chromatography column?
correct answers The most non-polar will elute first, as the polar compound will be stuck to the
stationary phase due to hydrogen bonding.
When making a chromatography column with alumina or slice gel, why is hexane often used?
correct answers Because it will not dissolve the aluminum or silca gel and they will sink.
Why is sand used when a chromatography column is prepared? correct answers The sand helps
keep the bottom and top ends of the stationary phase flat and even
Trans-stilbene Experiment
If there is unreacted 2-bromo-1,2-diphenylehtanol left in your crude stilbene oxide, what will
happen to this impurity during column chromatography? correct answers The impurity will stay
on the column longer than the epoxide product, thus the epoxide product will be purified.
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller FullyFocus. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $11.09. You're not tied to anything after your purchase.
