TZ757300 From United States of America, joined Aug 2005, 2836 posts, RR: 7 Reply 1, posted (6 years 2 months 2 weeks 14 hours ago) and read 1202 times:
NWOrientDC10 From United States of America, joined Mar 2005, 1389 posts, RR: 4 Reply 2, posted (6 years 2 months 2 weeks 12 hours ago) and read 1192 times:
Quoting Dc9northwest (Thread starter): So, guys, the USA High School National Chemistry Olympiad is this weekend. Is anyone here except me gonna take part in this competition?
JBirdAV8r From United States of America, joined Jun 2001, 4459 posts, RR: 22 Reply 3, posted (6 years 2 months 2 weeks 10 hours ago) and read 1186 times:
Have fun!
My girlfriend's a chemistry major...I'm guessing she's a little like you. She's the "I'm-so-upset-I-got-an-A-minus-on-my-pchem-exam" type of girl. She had a nightmare about nitrating a benzene ring or something to that effect.
NWOrientDC10 From United States of America, joined Mar 2005, 1389 posts, RR: 4 Reply 4, posted (6 years 2 months 2 weeks 10 hours ago) and read 1185 times:
Quoting JBirdAV8r (Reply 3): She had a nightmare about nitrating a benzene ring or something to that effect.
She must be taking organic chemistry this year. I took organic twenty years ago and am so "rusty" in theory that I'm not sure if nitrating an aromatic molecule is replacing the hydrogen with a NH (2) or NO (2).
SmithAir747 From Canada, joined Jan 2004, 1599 posts, RR: 33 Reply 5, posted (6 years 2 months 1 week 6 days 17 hours ago) and read 1165 times:
Quoting NWOrientDC10 (Reply 4): I'm not sure if nitrating an aromatic molecule is replacing the hydrogen with a NH (2) or NO (2).
I took organic chemistry way back in 1995-1996, so I remember a bit of it.
Just for your information, "nitrating" an organic molecule means replacing one of its hydrogens with a NO2 group (nitrate); a nitrate is a functional group consisting of N with 2 Os attached. Did it jog your memory?
Of all the chemistry classes I took, organic was the only one I really understood--it's concrete and easy to visualise, compared with general and inorganic types of chemistry which rely largely on mathematics and computation (with which I struggle). I am a concrete, not an abstract, person!
SmithAir747
[Edited 2007-03-10 23:07:19]
I will praise thee; for I am fearfully and wonderfully made... (Psalm 139:14)
NWOrientDC10 From United States of America, joined Mar 2005, 1389 posts, RR: 4 Reply 6, posted (6 years 2 months 1 week 6 days 16 hours ago) and read 1159 times:
Quoting SmithAir747 (Reply 5): Just for your information, "nitrating" an organic molecule means replacing one of its hydrogens with a NO2 group (nitrate); a nitrate is a functional group consisting of N with 2 Os attached.
Actually, I think a nitrate is an NO(3) group while an NO(2) is nitrite, NH(2) groups are called amines, I think. Anyway, your memory is still better than mine
Quoting SmithAir747 (Reply 5): Of all the chemistry classes I took, organic was the only one I really understood--it's concrete and easy to visualise, compared with general and inorganic types of chemistry which rely largely on mathematics and computation (with which I struggle).
This is true, although I did like biochemistry.
Quoting SmithAir747 (Reply 5): I am a concrete, not an abstract, person!
I'm more abstract, go figure.
Quoting SmithAir747 (Reply 5): I took organic chemistry way back in 1995-1996, so I remember a bit of it.
I took organic in 1986-1987. What text book did you have. We had Morrison and Boyd.
I like chemistry. To me, it is the structure of matter.
It's been a while since I had a conversation like this.
Dc9northwest From Romania, joined Feb 2007, 1735 posts, RR: 4 Reply 7, posted (6 years 2 months 1 week 6 days 12 hours ago) and read 1147 times:
Quoting NWOrientDC10 (Reply 6): Actually, I think a nitrate is an NO(3) group while an NO(2) is nitrite, NH(2) groups are called amines, I think.
Yup.
One of the answers on the test was amines.
Quoting SmithAir747 (Reply 5): Of all the chemistry classes I took, organic was the only one I really understood--it's concrete and easy to visualise, compared with general and inorganic types of chemistry which rely largely on mathematics and computation (with which I struggle). I am a concrete, not an abstract, person!
I never had an organic chemistry class yet I still got most of it after I read the textbook (a minimal one though)... I don't find this subject "life-threatening" like most of my classmates, however, I'm better at math and physics. So I can't say I dislike inorganic chemistry.
I took the test today, should get just over half the answers right. Anyway, in class we only did *maybe* 25% of the material on this olympiad. So... I don't know exactly.
Walter747 From United States of America, joined Oct 2006, 1440 posts, RR: 5 Reply 8, posted (6 years 2 months 1 week 6 days 12 hours ago) and read 1146 times:
Quoting Dc9northwest (Thread starter): So, guys, the USA High School National Chemistry Olympiad is this weekend. Is anyone here except me gonna take part in this competition?
Actually no, because my current grade in chemistry is a 66.
Zone1 From United States of America, joined Jan 2005, 1033 posts, RR: 7 Reply 9, posted (6 years 2 months 1 week 6 days 10 hours ago) and read 1139 times:
I took this test 4 years ago. Basically it was a painful way to spend a Saturday afternoon. I did good on the regional qualifying test, but the National test... ouch. I had no idea how to do the lab portion of the test.
JCS17 From United States of America, joined Jun 2001, 8065 posts, RR: 43 Reply 10, posted (6 years 2 months 1 week 6 days 10 hours ago) and read 1134 times:
YooYoo From Canada, joined Nov 2003, 6055 posts, RR: 53 Reply 11, posted (6 years 2 months 1 week 6 days 10 hours ago) and read 1132 times:
Quoting Dc9northwest (Thread starter): the USA High School National Chemistry Olympiad is this weekend. Is anyone here except me gonna take part in this competition?
Finally the real reason CastleIsland can't make the LAS meet.
I am so smart, i am so smart... S-M-R-T... i mean S-M-A-R-T
NWOrientDC10 From United States of America, joined Mar 2005, 1389 posts, RR: 4 Reply 12, posted (6 years 2 months 1 week 6 days 2 hours ago) and read 1119 times:
TZ757300 From United States of America, joined Aug 2005, 2836 posts, RR: 7 Reply 13, posted (6 years 2 months 1 week 6 days 2 hours ago) and read 1117 times:
NWOrientDC10 From United States of America, joined Mar 2005, 1389 posts, RR: 4 Reply 14, posted (6 years 2 months 1 week 6 days 2 hours ago) and read 1115 times:
Quoting TZ757300 (Reply 13): Unfortunately, thats a physics classroom, judging by the things on the walls. (yeah, Im a nerd like that)
TZ757300 From United States of America, joined Aug 2005, 2836 posts, RR: 7 Reply 15, posted (6 years 2 months 1 week 6 days 1 hour ago) and read 1104 times:
NWOrientDC10 From United States of America, joined Mar 2005, 1389 posts, RR: 4 Reply 16, posted (6 years 2 months 1 week 5 days 23 hours ago) and read 1091 times:
SmithAir747 From Canada, joined Jan 2004, 1599 posts, RR: 33 Reply 17, posted (6 years 2 months 1 week 5 days 22 hours ago) and read 1084 times:
Quoting NWOrientDC10 (Reply 6): Quoting SmithAir747 (Reply 5):
I took organic chemistry way back in 1995-1996, so I remember a bit of it.
I took organic in 1986-1987. What text book did you have. We had Morrison and Boyd.
For the life of me, I cannot remember which textbook I had! All I know is that it was published by the time I took organic chemistry in 1995-1996. I have trouble remembering authors' names! It was a thick, heavy book. It was well-illustrated in colour. I am thinking Vollardt or something like that. If I saw the book somewhere, or a picture of it, I would remember.
(I was attending Indiana Univ.-Purdue Univ. Fort Wayne, as a Purdue biology major).
I also used one of those plastic colour-coded organic molecular-model kits.
SmithAir747
I will praise thee; for I am fearfully and wonderfully made... (Psalm 139:14)
NWOrientDC10 From United States of America, joined Mar 2005, 1389 posts, RR: 4 Reply 18, posted (6 years 2 months 1 week 5 days 22 hours ago) and read 1081 times:
Quoting SmithAir747 (Reply 17): For the life of me, I cannot remember which textbook I had! All I know is that it was published by the time I took organic chemistry in 1995-1996. I have trouble remembering authors' names! It was a thick, heavy book. It was well-illustrated in colour. I am thinking Vollardt or something like that. If I saw the book somewhere, or a picture of it, I would remember.
(I was attending Indiana Univ.-Purdue Univ. Fort Wayne, as a Purdue biology major).
I also used one of those plastic colour-coded organic molecular-model kits.
SmithAir747
Let us discuss organic chemistrry
Topic: trans - Fatty acids; it is centered around the ethene group. Here's a pop quiz: What's the counter part to trans - Fatty acids?
NWOrientDC10 From United States of America, joined Mar 2005, 1389 posts, RR: 4 Reply 19, posted (6 years 2 months 1 week 5 days 20 hours ago) and read 1075 times:
SmithAir747 From Canada, joined Jan 2004, 1599 posts, RR: 33 Reply 20, posted (6 years 2 months 1 week 5 days 20 hours ago) and read 1075 times:
Quoting NWOrientDC10 (Reply 18): Topic: trans - Fatty acids; it is centered around the ethene group. Here's a pop quiz: What's the counter part to trans - Fatty acids?
The counterpart to trans fatty acids are cis fatty acids. Trans (and cis) fatty acids are unsaturated fatty acids, which are opposite to saturated fatty acids.
Unsaturated fatty acids=fatty acids with one or more double bonds between carbons in the chain.
Trans fatty acids=have the double bond between Cs in the trans configuration (a straighter, rather than kinked, configuration).
Cis fatty acids=the double bond between Cs is in the cis configuration ("kinked").
In contrast to unsaturated fatty acids (the aforementioned cis and trans fatty acids), saturated fatty acids have no double bonds between Cs anywhere in the chain, and are more flexible.
SmithAir747
I will praise thee; for I am fearfully and wonderfully made... (Psalm 139:14)
TZ757300 From United States of America, joined Aug 2005, 2836 posts, RR: 7 Reply 21, posted (6 years 2 months 1 week 5 days 16 hours ago) and read 1058 times:
Quoting NWOrientDC10 (Reply 16): If there is a fifth factor, what is it? "Name that tune"
In your terms, (x - x(0)) = vt + 1/2 at(squared)
Its plugging in v final instead of v initial. If you see these as interchangeable, then yes, there are 4, but i see them as 2 different variables, so i see it as 5.
Quoting NWOrientDC10 (Reply 16): If doing some simple research "kills you" (I'm paraphrasing here) then maybe you should stay in bed and just lie there.
Its not the simple research, its just typing equations in without symbols. Every time I try to write equations without symbols, it looks like crap
NWOrientDC10 From United States of America, joined Mar 2005, 1389 posts, RR: 4 Reply 22, posted (6 years 2 months 1 week 5 days 13 hours ago) and read 1051 times:
Quoting SmithAir747 (Reply 20): nsaturated fatty acids=fatty acids with one or more double bonds between carbons in the chain.
Mono unsaturated lipids have one double bond. Polyunsaturated compounds have more than one double ("ene") bond.
Quoting SmithAir747 (Reply 20): Trans fatty acids=have the double bond between Cs in the trans configuration (a straighter, rather than kinked, configuration).
Quoting SmithAir747 (Reply 20): Cis fatty acids=the double bond between Cs is in the cis configuration ("kinked").
This is correct. The cis (aka kinked) configuration is unstable, probably because of crowding amongst the respective "R" and "R' " groups. I'm also thinking that torsional strain is part of the cause of instability of cis compounds.
NWOrientDC10 From United States of America, joined Mar 2005, 1389 posts, RR: 4 Reply 23, posted (6 years 2 months 1 week 5 days 13 hours ago) and read 1047 times:
Quoting TZ757300 (Reply 21): Its not the simple research, its just typing equations in without symbols. Every time I try to write equations without symbols, it looks like crap
Kieron747 From , joined Dec 1969, posts, RR: Reply 24, posted (6 years 2 months 1 week 5 days 5 hours ago) and read 1037 times:
I love organic chemistry, I did my degree in Medicinal chemistry and Biochemistry, and my Ph.D in synthetic organic chemistry. I made phthalocyanines (see pic) to treat skin cancer. Great stuff!
CastleIsland From , joined Dec 1969, posts, RR: Reply 25, posted (6 years 2 months 1 week 4 days 22 hours ago) and read 1028 times:
Quoting NWOrientDC10 (Reply 22): The cis (aka kinked) configuration is unstable, probably because of crowding amongst the respective "R" and "R' " groups. I'm also thinking that torsional strain is part of the cause of instability of cis compounds.
It's not so much an instability issue as it is an entropy issue. This affects the "chemical preference" of which isomer is formed. You are correct that in the cis- configuration, the R-groups are more crowded; hence, there is less chance that this isomer will be formed. Once formed, it cannot naturally convert to the trans- form just because the cis- form exhibits more steric hinderance.
Put another way, if a reaction can produce either cis- or trans- isomers and steric hindrance of the R-groups comes into play, the less hindered trans- form will be favored.
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