Monday, November 7, 2011

Chapter 6

Any questions on Chapter 6 material? Ask them here.

27 comments:

Anonymous said...

So what came of the problems on the MasteringChemistry answer key?

Will we be credited back for the correct answers/ambiguity?

Scott McIndoe said...

I checked with the course coordinator on Friday about this issue; no news at this stage. However, if he can't fix it so more than one answer is marked correctly, everyone will get a bonus mark.

Anonymous said...

When will the solutions of the Midterm 2 be up? Also, your review sessions were very helpful! Thanks

Scott McIndoe said...

Soon, & yr welcome

Anonymous said...

Hi Dr. McIndoe,

In naming organic compounds, I'm having trouble figuring out what the longest carbon chain is when it comes to the bends in the molecule. I can't really find a good explanation anywhere on how to pick it properly!

Thank you!

Anonymous said...

There's a lot of information in chapter 6 of our text regarding the reactions that form the various functional groups (ie: ethers can be formed during a condensation reaction). Just wondering if this is important information to know as we didn't cover it.

Thanks

Anonymous said...

In question 4 in of the notebook, the solution arranges two carbon atoms in a line and the other is part of a subsituent. Why is not correct to put all three of them in a line with a structure like

H H Cl
1 1 1
H-C-C=C
1 1
H H

Anonymous said...

Are there answers available for the sample finals in the back of the lab manual? Thanks

Anonymous said...

In the assignment 6 on masteringchemistry Question 24.29 Part B has a Carbon with five bond on the middle atom. Is this a mistake, am I just really stupid or is this what happens in a double bond and methyl group in one?

Anonymous said...

Question 24.29 b on masterchem gave me problems too, I couldn't figure out what I was doing wrong until you said that.

Scott McIndoe said...

Re: organic compounds - come and see me, it is hard to explain without drawing structures.

Re: reactions of functional groups; the most important reactions are covered in your lecture book, so the other examples are less important and less likely to be examined.

Re: q4, I don't really understand your question, sorry! Please come and ask me about it in person.

Re: sample finals - ChemSoc sells past exams with model answers, probably next week, on the 3rd floor of Elliott.

Re: 24.29b - I haven't checked it, but it definitely sounds wrong. Ignore that question!

Anonymous said...

For the Mastering Chemistry quiz, in order to "draw the formula" do we just draw the lines(vertices representing carbons) or full like ch3ch2ch3?

Anonymous said...

For the quiz due tonight, I answered "chiral" for a question. However, the program interpreted my answer as a strange symbol that looks like an x to the power of ral. It looked sort of like x^ral, but in place of x was the strange symbol.

Why did this happen, and will I lose the mark?

Anonymous said...

How do you know how many isomers a given molecule has just by seeing the molecular formula? Do you have to draw it out every time? That seems excessive for molecules with many isomers..

Anonymous said...

Mastering Chemistry is terribly ambiguous when it comes to writing out answers/drawing molecules.

For drawing 2-methyl-4-propylnonane I drew the exact same thing but reversed and using a bigger space and still got it wrong.

Scott McIndoe said...

Re: MasteringChemistry (3 questions) - agreed, entering answers can be frustrating, which is why we posted assignments for practice. Getting it right takes a bit of trial and error. Thanks for your feedback ("chi" is a Greek letter that looks like an x, but that seems like a funny response). I can't actually act on any MasteringChemistry questions - please contact UVICMasteringHelp@gmail.com or the course coordinator, Sandy Briggs.

Re: number of isomers - yes, you have to draw them out. For more complex examples, yes, there will be dozens (hundreds!) but you'll mostly encounter simpler examples that will enable you to demonstrate your mastery of the concept without having to draw an excessive number.

Anonymous said...

What are your office hours sir?

Also what is the maximum amount of isomers that can be tested? Because the one on MC was ridiculous (9)


And will we receive 1 mark on the previous assignment since there were 2 answers to a question?

Scott McIndoe said...

Re: office hours - 3:30-4:30 Tues and Thur, but they will be extended this week. I'll announce them in class tomorrow.
9 is at the top end, certainly.
Re: the previous question - yes, you will get a mark for the ambiguity, or if that isn't possible - the course coordinator is working on it - everyone will get it right.

oRyanC said...

Question 9 of Graded quiz 7 marked optical isomers wrong and said the answer was enantiomers. Is there a difference between "enantiomers" and "optical isomers"?

Scott McIndoe said...

Please query the course coordinator, Sandy Briggs, about online quizzes.

Anonymous said...

In the textbook, there is a question:

what are the two compounds containing one nitro group formed when naphthalene reacts with nitric and sulfuric acids.

Since sulfuric acid serves as a catalyst..the only product formed would be nitronapthalene and water? where are they getting two from? are they separating the napthalene??

Anonymous said...

when it comes to naming compounds...there is a lot of confusion...
such as -al for all aldehydes...eg ethanal rather than ethal

or propionate rather than propate

the pre-fix is described to be the amount of carbons..then why does it differ?

Anonymous said...

what would be correct?

phenyl butyrate
phenyl butanoate
penyl butate

I chose the second since the ending has to be oate...but book disagrees

Anonymous said...

Dr. McIndoe

for question 2 in the lecture notebook for chapter 6.

wouldn't the second molecule be trans-4-methyl-2-pentene

because you can have a cis isomer as well?

am i correct?

Scott McIndoe said...

Re: nitro groups; this is the same as one of the clicker questions asked in class. Basically, there are two different sites on naphthalene that the -NO2 group can go. Have a look at the clicker question answers for this one.

Re: naming compounds - just stick to the scheme I taught in class i.e. -al for aldehydes, -oate for esters, etc. The textbook is FULL of trivial names, which I agree is confusing.

Re: your answer is correct, assuming the compound is CH3CH2CH2COOC6H5. What did the book say was correct?

Anonymous said...

The video doesn't include the trans for the answer..

Scott McIndoe said...

Oops, missed a question. You're right, it should have "trans". Thanks! We'll fix that (but not in the next 2 days...).