Quiz 3 Preparation
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Quiz 3 Preparation
For the question #2 on page 43, it states to name the compound CH3CH(CH3)CH(CH2CH3)C(CH3)3.
I have named the compound 3-ethyl-2,2,4-trimethyl pentane but the answer says its 2,2,4-trimethyl-3-ethyl pentane. Why?
I have named the compound 3-ethyl-2,2,4-trimethyl pentane but the answer says its 2,2,4-trimethyl-3-ethyl pentane. Why?
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Re: Quiz 3 Preparation
for question number 5 on the first quiz, why is Iodine chosen as the starting point rather than Bromine? does it matter?
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Re: Quiz 3 Preparation
@chrispolo15 It does matter. Priority is based on atomic number of the atom bound to the carbon and I has a higher number than Br.
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Re: Quiz 3 Preparation
Would someone be able to walk through how to get to either answer ?? I am still getting confused on these types of questions.
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Re: Quiz 3 Preparation
Can anyone explain the difference between benzene and phenyl ring? How do we distinguish between the two?
Re: Quiz 3 Preparation
Benzene has 6 hydrogens to go with the 6 carbons that give it its structure. A phenyl ring has 6 carbon atoms, but only 5 hydrogen atoms.
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Re: Quiz 3 Preparation
In the first Quiz 3 Preparation on page 44 number 6 I named the compound using "neo", while the answer instead uses "tert". Would both answers be correct or is neo not used? If not, why is that?
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Re: Quiz 3 Preparation
chrispolo15 wrote:for question number 5 on the first quiz, why is Iodine chosen as the starting point rather than Bromine? does it matter?
I had the exact same question. I always thought that since bromine comes first alphabetically, it must be assigned the lower number. Therefore you Bromine would be numbered 1? Is this not the case?
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Re: Quiz 3 Preparation
Could someone draw out this compound and explain the different parts of the name in correspondence with the compound because I tried and I looked it up but its confusing me.
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Re: Quiz 3 Preparation
@Johnchou1A the Iodine gets ultimate priority since it has a higher atomic number, therefore, iodine should be 1 and bromine should be 3
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Re: Quiz 3 Preparation
Shelby Yee 1J wrote:@Johnchou1A the Iodine gets ultimate priority since it has a higher atomic number, therefore, iodine should be 1 and bromine should be 3
Do we look at the atomic number only when we deal with halogens as substituents then?
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Re: Quiz 3 Preparation
I thought priority was only considered when evaluating geometric isomers... in halogenated compounds the halogens are treated as substituents and are organized alphabetically. Double and triple bonds are still given priority.
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Re: Quiz 3 Preparation
Kimberly Govea 2L wrote:For the question #2 on page 43, it states to name the compound CH3CH(CH3)CH(CH2CH3)C(CH3)3.
I have named the compound 3-ethyl-2,2,4-trimethyl pentane but the answer says its 2,2,4-trimethyl-3-ethyl pentane. Why?
For this question, I would say that your answer is correct because when putting the substituents in alphabetical order, you would disregard the tri on methyl. Therefore if you compare methyl to ethyl, 'e' comes before 'm' making the correct order ethyl then trimethyl.
To be safe, I would recommend writing the answer as you did (using alphabetical order for the substituents).
Last edited by Reine Nakamura 1C on Mon Feb 29, 2016 6:51 pm, edited 2 times in total.
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Re: Quiz 3 Preparation
studdmuffin wrote:I thought priority was only considered when evaluating geometric isomers... in halogenated compounds the halogens are treated as substituents and are organized alphabetically. Double and triple bonds are still given priority.
Chem_Mod wrote:I believe the correct answer should be 1-bromo-3-iodo because all halogens have the same priority (also the same as alkyl groups so bromo<butyl<chloro<ethyl<iodo<methyl<propyl like this). And the first alphabetical substituent gets the lower number.
According to this response from one of the TA's/UA's, I believe the answer key was incorrect and it should be 1-bromo-3-iodocyclohexane.
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Re: Quiz 3 Preparation
Is number 2's (on the first quiz prep) IUPAC name 3-ethyl-2,2,4-trimethyl pentane and its common name 3-ethyl-2-methylneoheptane?
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Re: Quiz 3 Preparation
Curtis Ngo_4E wrote:Will we be asked about common names on the quiz? Or only IUPAC naming?
Hi my good pal Curtis,
I believe I read on another post from a TA that we will be asked about both common names and IUPAC naming.
Re: Quiz 3 Preparation
will there be the natural log stuff that didn't get covered on the last quiz?
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Re: Quiz 3 Preparation
In the course reader on page 87 the arrow from the C,C double bond would indicate that 2 electrons are moving correct ? Is that true however?
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Re: Quiz 3 Preparation
Please see my many quiz 3 answers at viewtopic.php?f=2&t=12738
Note: Quiz 3 Preparation Answers had two errors. They should be:
Q2. 3-ethyl-2,2,4-trimethyl-pentane
Q5. 1-bromo-3-iodocyclohexane
Note: Quiz 3 Preparation Answers had two errors. They should be:
Q2. 3-ethyl-2,2,4-trimethyl-pentane
Q5. 1-bromo-3-iodocyclohexane
Re: Quiz 3 Preparation
Hi is there supposed to be a - between the methyl and pentane? or could we just write it s 2,2,4-trimethyl-3-ethylpentane?
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Re: Quiz 3 Preparation
In the preparation 2, the answer of q5 is a structural formula, but the question asks for the molecular formula. Should the answer be C4H9Br?
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Re: Quiz 3 Preparation
jyc185 wrote:Hi is there supposed to be a - between the methyl and pentane? or could we just write it s 2,2,4-trimethyl-3-ethylpentane?
The answer is 3-ethyl-2,2,4-trimethyl-pentane or 3-ethyl-2,2,4-trimethylpentane.
I often insert - to make it easier for students to read.
3-ethyl-2,2,4-trimethylpentane would be the best way to write it.
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Re: Quiz 3 Preparation
Yuanming Mao 3J wrote:In the preparation 2, the answer of q5 is a structural formula, but the question asks for the molecular formula. Should the answer be C4H9Br?
Correct. The product is CH3CH2CHBrCH3 with a molecular formula C4H9Br.
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Re: Quiz 3 Preparation
Like on question #5, I understand that the slow step in an addition reaction is the limiting step, but will the slow step always be the 1st step as well?
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Re: Quiz 3 Preparation
Mane Zills wrote:Like on question #5, I understand that the slow step in an addition reaction is the limiting step, but will the slow step always be the 1st step as well?
For all reactions, no.
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Re: Quiz 3 Preparation
Just to clarify, do the parenthesis in the equations indicate a substituent?
eg:
CH3CH(CH3)....etc.
eg:
CH3CH(CH3)....etc.
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Re: Quiz 3 Preparation
303747052 wrote:Just to clarify, do the parenthesis in the equations indicate a substituent?
eg:
CH3CH(CH3)....etc.
Yes, parenthesis indicate substituents!
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Re: Quiz 3 Preparation
Mayvera Doaran 2H wrote:303747052 wrote:Just to clarify, do the parenthesis in the equations indicate a substituent?
eg:
CH3CH(CH3)....etc.
Yes, parenthesis indicate substituents!
Great, thank you for the reply.
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