A couple questions regarding Organic Chemistry

[fterh]

1) Cholesterol is an organic molecule that occurs in the blood stream. What type of compound is cholesterol?

 

A) an acid B) an alcohol C) an alkane D) an alkene

 

I guessed A because cholesterol comes from fats which are fatty acids. But the answer is B Why is that?

 

2) A compound known in industry as "MTBE" is used as an additive in lead-free petrol. The structural formula of MTBE is shown.

 

Why isn't this the answer?

 

P/S: I know this belongs in the Organic Chemistry sub-forum, but it's really dead in there and I hope to get my answers ASAP :-)

[DJBruce]

This seems like homework so I won't give you the answer to number one, but here are some questions that might help you get the answer.

 

-What is functional group that makes something an alcohol?

-Have you looked at a picture of cholesterol?

-What is the ending added to words that are alcohols?

[cypress]

Another minor point is that fats are not generally derived from fatty acids.

 

On your second question there are two reasons why the second answer is not a possible answer to the question. One is that MBTE is an acronym for Methyl Tertiary-Butyl Ether. The compound name describes the organic structure which is made up of two parts, tertiary butane/butyl group, and an ether. The left side of the first is one of those groups and the right side of the molecule is the other. Perhaps you can identify these groups and see why the first is the only possible solution. The second reason is that carbon bonds don't form at 90 degree angles, (what angles are possible based on orbital bonding?) so the four ringed carbon group is not stable.

[fterh]

This seems like homework so I won't give you the answer to number one, but here are some questions that might help you get the answer.

 

-What is functional group that makes something an alcohol?

-Have you looked at a picture of cholesterol?

-What is the ending added to words that are alcohols?

 

Nah it isn't homework It's further revision for my upcoming test on organic chemistry

 

Anyway to answer your questions:

 

1) hydroxyl, -OH

2) nope, one isn't provided anyway

3) anol

 

But cholesterol doesn't have the "anol" appended to it.

---

Merged post follows:

Consecutive posts merged

Another minor point is that fats are not generally derived from fatty acids.

 

On your second question there are two reasons why the second answer is not a possible answer to the question. One is that MBTE is an acronym for Methyl Tertiary-Butyl Ether. The compound name describes the organic structure which is made up of two parts, tertiary butane/butyl group, and an ether. The left side of the first is one of those groups and the right side of the molecule is the other. Perhaps you can identify these groups and see why the first is the only possible solution. The second reason is that carbon bonds don't form at 90 degree angles, (what angles are possible based on orbital bonding?) so the four ringed carbon group is not stable.

 

I think I get it, thanks! :D:D

[Horza2002]

I feel the need to point out that cyclobutane does exist and can be made quiet easily, even though it is unstable relative to larger rings. But once you know what the acronym it should be obvious why thats the structure and not your proposed one.

[DJBruce]

Nah it isn't homework It's further revision for my upcoming test on organic chemistry

 

Anyway to answer your questions:

 

1) hydroxyl, -OH

2) nope, one isn't provided anyway

3) anol

 

But cholesterol doesn't have the "anol" appended to it.

 

1) Yep that is right.

2) Well if you have ever seen the picture you would notice it contains an alcohol functional group.

3) The actual ending for an alcohol is "ol".

 

This means that cholesterol contains the ending for an alcohol, and therefore must be an alcohol.