Some more Orgo questions

[girlspowerss]

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I appreciate some help on these questions.

After going through a whole bunch of MCAT OChem questions, I'm stuck on these and the internet is not helping me out. Could any Ochem folks give me a hand?

The oxidation of alcohols by pyridinium chlorochromate can form two different products, depending on
whether water is present. These two products are:
A. a peroxide and an aldehyde.
B. a peroxide and a carboxylic acid.
C. a carboxylic acid and a ketone.
D. a ketone and an aldehyde.​

E. a carboxylic acid and an aldehyde.

Hydroboration–oxidation of an olefin converts the alkene into the:
A. Markovnikov alcohol.
B. anti-Markovnikov alcohol.
C. epoxide.​

D. anti-Markovnikov ketone.

The product of an aldol condensation is:
A. an​

​

​

​

a,b-unsaturated carbonyl compound.
B. a 1,3-dicarbonyl compound.
C. a 1,5-dicarbonyl compound.​

D. a 1,3-diol compound.

The progress of the following oxidation reaction can easily be monitored by infrared spectroscopy:
Alcohol / (oxidant)​

​

​

​

® Aldehyde. In what region of the IR spectrum does the carbonyl stretch of the
aldehyde appear?
A. Around 3400 cm–1​

B. Around 2100 cm​

​

​

​

–1​

C. Around 1700 cm​

​

​

​

–1​

D. Around 1200 cm–1

A compound has the following​

​

​

​

1H NMR spectrum: d 2.5 (1H, t, J = 3 Hz); 3.1 (1H, s); 4.3 (2H, d, J = 3 Hz)
ppm. The 1H NMR resonance at 4.3 ppm corresponds to protons that are coupled to how many other
protons?
A. 0
B. 1
C. 2​

D. 3

Which of the following most likely describes the pK​

​

​

​

a of the ammonium group of a zwitterionic amino acid?
A. pKa < 2
B. 2 < pKa < 4
C. 4 < pKa < 10​

D. 10 < pKa

 

[PiBond]

she's wanting us to help her get a job at TPR

Good luck getting past training....you won't make it if you have to poll SDN for the answers

 

[girlspowerss]

why wont i make it

 

[BerkReviewTeach]

I appreciate some help on these questions.

After going through a whole bunch of MCAT OChem questions, I'm stuck on these and the internet is not helping me out. Could any Ochem folks give me a hand?

The oxidation of alcohols by pyridinium chlorochromate can form two different products, depending on
whether water is present. These two products are:
A. a peroxide and an aldehyde.
B. a peroxide and a carboxylic acid.
C. a carboxylic acid and a ketone.
D. a ketone and an aldehyde.​

E. a carboxylic acid and an aldehyde.

Hydroboration–oxidation of an olefin converts the alkene into the:
A. Markovnikov alcohol.
B. anti-Markovnikov alcohol.
C. epoxide.​

D. anti-Markovnikov ketone.

The product of an aldol condensation is:
A. an​

​

​

​

a,b-unsaturated carbonyl compound.
B. a 1,3-dicarbonyl compound.
C. a 1,5-dicarbonyl compound.​

D. a 1,3-diol compound.

The progress of the following oxidation reaction can easily be monitored by infrared spectroscopy:
Alcohol / (oxidant)​

​

​

​

® Aldehyde. In what region of the IR spectrum does the carbonyl stretch of the
aldehyde appear?
A. Around 3400 cm–1​

B. Around 2100 cm​

​

​

​

–1​

C. Around 1700 cm​

​

​

​

–1​

D. Around 1200 cm–1

A compound has the following​

​

​

​

1H NMR spectrum: d 2.5 (1H, t, J = 3 Hz); 3.1 (1H, s); 4.3 (2H, d, J = 3 Hz)
ppm. The 1H NMR resonance at 4.3 ppm corresponds to protons that are coupled to how many other
protons?
A. 0
B. 1
C. 2​

D. 3

Which of the following most likely describes the pK​

​

​

​

a of the ammonium group of a zwitterionic amino acid?
A. pKa < 2
B. 2 < pKa < 4
C. 4 < pKa < 10​

D. 10 < pKa

You should throw out question #2, because that hasn't been tested on the MCAT in six years.

For question #1, think about how many Hs are on a primary alcohol and what oxidation does to those Hs. Replace them with whatever is gained in oxidation and then you have your answer.

For question #3, think about how a deprotonated carbonyl compound could react as a nucleophile with a neutral form of itself.

For question #4, it's straight memorization.

For question #5, you need to determine what the 2H means (which may end up being irrelevant) and what the d means (which may be very relevant). One of those two terms will answer your question.

For question #6, this is another case of pure memorization. Any chemistry text book with an amino acid chapter will give you this answer.

All in all, these are incredibly basic and simple organic chemistry questions. If you don't know them, then you should be fair to yourself and not take a job teaching this material. Let's say someone comes along here to feed you the answers, you get past the interview and next thing you know you have a class of wannabe doctors counting on you to help them prepare for the MCAT. Is that fair to them?

why wont i make it

I'm assuming he's thinking that if you need help on basic questions, then you won't make it past the interview. Your job is to learn the material and prove him wrong. So far though, he's looking like he's right.

 

[TTigers70]

A lot of your questions can be answered knowing definitions and basic uses of the mechanisms listed. If you intend on teaching this material to others, make sure you yourself know it. Hydroboration-oxidation is a crucial to any kind of alkene chemistry. Aldol condensation follows a simple pattern but is essential to understand when discussing carbonyls.

 

[Rayhaan]

this sort of reminds me of an mcat prep course I took last year from a pretty much third party company. the teacher had no clue about organic at all. you should really know this stuff, aldol condensatons and the IR spectrum of aldehyde, really?

 

[wallmartcart]

I disagree with what the other people have said. Just because you can't answer these does not mean you won't make it. That is what prepping is for. You can't remember every little detail all the time about every class you took. You will be fine as long as you do the proper prep work so that you know the material you have to teach that class.