1.ÝÝÝÝÝ
ÝÝÝÝÝÝ For all of them, I
am going to describe the carbon and ignore the presence of the hydrogens, which
fill the rest of the four possible bonding sites on each carbon atom.
-straight chain of five carbon atoms
-a chain of four carbon atoms with the fifth one coming off of the
second carbon in the chain
-a plus shape, with a central carbon, and carbons bonded to each
of the 4 bonding sites on it
All other possibilities which I could come up with were able to be
created by the inherant flexibility of a single bond
I found 6 different isomers for C5H12.Ý One is a straight line; one is like steps-carbon is connected
upwards to another carbon, over to another, up to another, then over again; the
next one looks like a chair with a carbon connected upwards to another, then
over, and down and up; one looks like an x; another looks like a t; and the
last one is a bigger step than the other one that looks like a step-a carbon
connected upwards to another carbon then over to another, and over again, and finally
upwards to another carbon.
3Ö the first ( pentane) is a
straight chain of 5 carbons, the two end carbons have three bonds with hydrogen
and the middle three have two bonds with hydrogen each.Ý The second (2, methyl butane) is a chain of
four carbons, carbon one has three hydrogens, carbon two has one hydrogen and a
carbon, which has three hydrogens, carbon three has two hydrogens and carbon
four has three hydrogens.ÝÝ The third
(dimethyl propane) is a chain of three carbons in which the two end carbons
have three hydrogens each and the middle carbon has two adjacent carbons, each
with three hydrogens.
Ý1)Ý I
could draw four isomeres with a few variations on the last one.Ý The first is a line of five carbons
surrounded by H.Ý Next is a Central C
with four C's attatched to it.Ý Each of
the four outer carbons have H's attatched to them.Ý Then there
is a vertical line of three carbons with two more attatched horizontally to the
central Carbon with H's around each one.Ý
Finally one could line four C's up with a single carbon coming of of the
string perpendicularly.Ý H's would be
surrounding each carbon.Ý This
structure could be varied depending on which carbon the ether group was
attatched to.Ý I'm sure there are a ton
of other isomers and I racked my brain, but I couldn't come up with any more
for the life of me.
I drew
6 isomers.Ý The first isomer was a link
of 5 carbons together with two hydrogens attached to the three middle carbons
and three hydrogens attached to the two outter carbons.Ý The next 4 isomers have a link of 4Ý
carbons with the fifth carbon branching out from one of the other 4
carbons.Ý Since there are 4 different
carbons the fifth can be attached to, there are 4 different isomers.Ý The 3 carbons not connected to the fifth are
all surrounded by hydrogens and the fifth carbon is surrounded by 3
hydrogens.Ý The last isomer was a single
carbon in the middle with 4 carbons branching out from it.Ý Attachted to each of the 4 carbons are 3
hydrogens apiece.
I was
able to come up with four very distinct structures, with about 20 variations on
those structures.Ý The first and
simplest structure is a 5 carbon chain, with hydrogens taking up the rest of
the free bonds.Ý My second idea was a 3
carbon chain with a two carbon chain coming off of it.Ý This second chain could go in one of two
directions from three different carbons, giving us six possibilities.Ý A third structure would be a 3 carbon chain
with two carbons attached, separately forming metyl groups, to the chain.Ý I calculated 9 different combinations this
way, with hydrogens filling in the additional bonds.Ý One other possibility is a four carbon chain, with the fifth
carbon coming off of one of the four carbons, forming a methyl group.Ý I also experimented wih 3- 4- and 5-carbon
rings, but none of those panned out as a possibility.ÝÝÝÝ
Ý
I drew
7 molecules.Ý The first was a 5-carbon
chain with two hydrogens attatched to the three central carbon atoms and three
hydrogens attatched to the two outer carbon atoms.Ý
The
second was a cross-shaped molecule with a carbon in the middle, bonded to four
other carbons, each of which had three hydrogen bonds.Ý The third molecule was a four-carbon chain
with the second carbon bonded to (besides two carbons in the chain) another
carbon and a hydrogen.Ý The three outer
carbons were bonded to three hydrogens each.
The
next 2 molecules were 3-carbon chains with carbons bonded to two of the chain
members.Ý Each molecule varied its
pattern.Ý One end carbon was bonded to 3
hydrogens and the other end carbon was bonded to 2 hydrogens and a carbon.Ý The center molecule was bonded to one
hydrogen and one carbon.Ý The two outer
carbons were bonded to 3 hydrogens.
The
sixth molecule was similar to the last 2, but the middle carbon was bonded to 2
hydrogens and the outer carbons of the 3-carbon chain were bonded to 2
hydrogens and a carbon (each of which was bonded to 3 carbons).
The
final molecule was a tetrahedron with a carbon center bonded to 4 other
carbons, each of which was bonded to 3 hydrogens.
Not
Counting mirror images I could come up with about 4 different isomers, and from
each of those I could the mirror image, except for the hydrocarbon chain that
has no mirror image.Ý So first of all I
got the hydrocarbon chain: The 5 carbons each 3 with 2 H off of them and the
ends with 3.Ý Then I got the one with 3
carbons across, and a carbon coming off of the end C.Ý The Protruding C have 3 H attached and the 3 central C only have
2.Ý Then there was the Tetrahedral
shaped structure.Ý With a central C
bonded to 4 other C, each with 3 Hydrogens coming off of it (Distel saw this
one, I think he thinks more spacally than I do).Ý Also I got the planar version of this which is cross shaped, and
designed the same way, so I guess that is really the same one just differently
arranged.Ý I couldn't get any double
bonds to work out, because I either had two many H, or not enough C to go
around.Ý For the same reason the triple
bond didn't work out.
I came
up with 6 different isomers.Ý The first
one is with a Carbon chain with a Hydrogen attached all around it.Ý The second is a central Carbon with the
other 4 Carbons radiating off.Ý Off of
these Carbons there are 3 Hydrogens surrounding them.Ý The next one is a 3 Carbon chain with a Carbon attached to the
top and the bottom of the first Carbon with the Hydrogens filling other
spaces.Ý A 4 Carbon chain attached to
one of the Carbons and the Hydrogen around the Carbons where they fit.Ý This same idea can be used by moving where
each Carbon is placed off the 4 Carbon chain.Ý
A bent chain of Carbon can be made, but it can't be all connected, then
the Hydrogens can surrounding the others.Ý
Overall I found many isomers, by changing the position of where the
Carbon is linked off.
I was
able to draw 23 strustures.Ý For each
structure, Carbon has four bonds.Ý Any
bond that is not C-C, assume to be the Hydrogen.
1.Ý a chain of 5 Carbons in a row, H's circling
2.Ý chain of 4 carbons, the 5th C branching up
from the 2nd C
3.Ý chain of 4 C's, 5th C branching down from
the 2nd C
4.Ý chain of 4 C's, 5th C branching up from the
3rd C
5.Ý chain of 4 C's, 5th C branching down from
3rd C
6.Ý chain of 3 C's, a C branching up from the
2nd and 3 C
7.Ý same as #6, but branching down
8.Ý chain of 3 C's, a C branching down from the
1st and 2nd C
9.Ý same as #8, but branching up
10.
chain of 3 C's, a c branching down from the 1st and 3rd C
11.
same as #10, but branching down
12.
chain of 3 C's, 2 C's branching down from the 1st C
13.
same as #12, only branching up
14.
chain of 3 C's, 2 C's branching down from the 2nd C
15.
same as #14, only branching up
16.
chain of 3 C's, 2 C's branching down from the 3rd C
17.
same as #16, but branching up
18.
chain of 3 C's, 1 C branching up from the 1st and 1 down from the 2nd
19.
chain of 3 C's, 1 C branching up from the 1st and 1 down from the 3rd
20.
chain of 3 C's, 1 C branching up from the 2nd and 1 down from the 3rd
21.
chain of 3 C's, 1 C branching down from the 1st and 1 up from theÝ 2nd
22.
chain of 3 C's, 1 C branching down form the 1st and 1 up from the 3rd
23.
chain of 3 C's, 1 C branching down from the 2nd and 1 up from the 3rd
ÝÝÝÝÝÝÝ I found three main isomers using
C5H12.Ý They are:
ÝÝÝÝ 1.Ý
A chain of five carbons surrounded by the remaining twelveÝÝÝ
ÝÝÝÝÝÝ hydrogens.Ý This is called Pentane.
ÝÝÝÝ 2.Ý
A chain of four carbons with the fifth carbon attached to the
ÝÝÝÝÝÝ second carbon in the chain.Ý This is called 2,methyl butane
ÝÝÝÝÝÝ because the methyl is connected to the
second carbon in the butane
ÝÝÝÝÝÝ sequence.
ÝÝÝÝ 3.Ý
A chain of three carbons that has a carbon attached to the ìtopî
ÝÝÝÝÝÝ and ìbottomî of the second carbon in
the chain of three.Ý This is
ÝÝÝÝÝÝ called 2,2dimethyl propane.
4
structures
1.
chain of 5 carbons
2.
chain of 4 carbons with a CH3 grouup off of one of the inside carbons
3. chain
of 3 carbons with CH3 groups off of an outside and the middle carbons
4. a
central carbon surrounded by 4 CH3 groups
Ý
1.Ý A 5-Carbon chain surrounded by hydrogen.
2-5.Ý A 4-Carbon chain with a carbon above one of
the other four carbons.Ý All carbons surrounded
by hydrogen.
6-9.Ý A 4-Carbon chain with a carbon below one of
the other four carbons.Ý All carbons
surrounded by hydrogen.
10-12.Ý A 3-Carbon chain with the two remaining
carbons above two of the three carbons (e.g.Ý
above carbon 1 and carbon 2; above carbon 1 and carbon 3).Ý All carbons surrounded by hydrogen.
13-15.Ý A 3-Carbon chain with the two remaining
carbons below two of the three carbons.Ý
All carbons surrounded by hydrogen.
16-24.Ý A 3-Carbon chain with one carbon above the
chain and one carbon below the chain (e.g.Ý
above carbon 1 and below carbon 1; above carbon 1 and below carbon 2,
etc.)Ý All carbons surrounded by
hydrogen.
I could
only draw around ten isomers of C5H12. Most are variations of a line structure
with alternating methyl groups, and one ringed structure. A couple had a three carbon base with
one methyl group at each end on alternating sides. One was tetrahedral and one
was trigonal planar. I am trying to think of more variations, and I know I am
missing a few, but nothing seems to work out. I have trouble with isomers for
some reason. If we could work on them more, I would greatly appreciate it. I
guess we will have to see if the rest of the class has trouble or if I am just
isomerically impaired. :)
The are
three isomers of the hydrocarbon containing five carbons and twelve
hydrogens.Ý The first is a continuous
chain of five carbons.Ý The first is
connected to the second.Ý The second is
connected to the first and third.Ý The
third is connected to the second and fourth etc. ÝThree hydrogens are bonded to each of the end carbons and two
hydrogens are bonded to each of the three remaining carbons.Ý The second isomer consists of four carbons
in a row with a fifth carbon bonded to the second carbon in the chain.Ý The second carbon also has one hydrogen
bonded to it.Ý The two end carbons and
the one bonded to the second carbon each has three hydrogens.Ý The remaining two are bonded to two
hydrogens each.Ý The third isomer
consists of a central carbon bonded to four other carbons.Ý The central carbon is bonded to no
hydrogens.Ý Each of the other four is
bonded to four hydrogens.
I
thought I had drawn 7, but when I showed them to Aaron Harnar he informed me
that I only had three because of the tracing carbon with a pencil rule. One looks
like two mountains of connected carbons with hydrogens surrounding them. The
second one looks like a cross of carbons also with the hydrogens surrounding
the carbons. The third one looks like a upside down v of carbons with a carbon
flag on top and the surrounding hydrogens.
There
are 5 different isomers of C5H12.Ý The
first one is a straight chain of the five carbon atoms, each surrounded by
hydrogen to give each carbon four bonds.Ý
The second is a chain of four carbon atoms with a CH3 group off the
second C atom.Ý The third is a chain of
four carbon atoms with a CH3 group off the third C atom.Ý The fourth is a chain of three carbon atoms
with two CH3 groups off the first carbon atom.Ý
A mirror image (two CH3 grops off the third C atom) can also exist.Ý The fifth isomer is a chain of three carbon
atoms with two CH3 groups off the center C atom.Ý Other arrangements, such as a chain of four C atoms with a CH3
group off the first C atom, can be treated as a straight chain.
Ý
I drew
five isomers for C5H12, but there are more that can be derived from these
five.Ý Each Carbon is surrounded by four
bonds, be it to another Carbon, or a Hydrogen.
a)
c-c-c-c-cÝ This is a straight chain of
five Carbons.Ý However, there can be a
kink or many kinks in the chain of Carbons, but this structure is still one
Carbon bonded to a maximum of two other Carbons.
b) Off
of the second Carbon in a straight chain of four Carbons is a methyl
group.Ý This methyl group may also be
off of the third Carbon, reading from left to right in a straight chain of four
Carbons.Ý These methyl groups may be
linked either above or below the Carbons it is bonded to.Ý Therefore it is a link of four Carbons with
three linked Carbon to Carbon, and one linked to three Carbons.Ý These isomers may be considered to be the
same in structure with simply different locations around the chain of Carbons.
c) In a
straight chain of three Carbons, a two Carbon chain linked onto the second
Carbon, again either above or below the Carbon in the three Carbon chain.
d) Here
the Carbons form a cross.Ý In a straight
chain of three Carbons, a methyl group coming off of the second Carbon in two
directions, on paper one up and one down.
e)Ý In a straight chain of three Carbons have a
methyl group come off either the first or the last Carbon in two directions,
again on paper one up and one down.Ý
These structures may be considered to be the same.
I came
up with with four isomers.Ý The first
drawing has all the carbons linked together in a single chain (5 carbons in a
row) with hydrogens surrounding it.Ý The
second isomer is similar to the first except the carbon at the end is linked to
the third carbon in the row, and hydrogens also surround the carbons.Ý The third structure has the carbons linked
together in the form of an addition sign with hydrogens surrounding the
carbons.Ý And finally, the fourth
drawing has three carbons linked to one another in a row and two carbons linked
together to the middle of the three carbonsÝ
This also has hydrogens surrounding the carbons.
three.
ÝÝ (1) all 5 carbons line up linearly.
ÝÝ (2) one carbon is center and other four
sround it.(the center one connected with 4 carbons)
ÝÝ (3) four carbons form linear and the other
bond with the second/third one.
2
straight lines of C, one verticle, one horizontal with H off of
each C.
ÝÝÝÝ One Cross of Cs with H off the 4
noncentral Cs.
ÝÝÝÝ 4 Ts, one upright, one upside down, one
to the right and one to the
left
with Hs
ÝÝÝÝ 4 Ls, again positioned like the Ts with
Hs filling all open C bonds
ÝÝÝ Ý4
off center Ts two upright, two upside down, with H off the Cs
ÝÝÝÝ (I hope you understand what I'm trying to
describe.Ý All single
bonds,
no dbls)
Three isomers can be drawn from
C5H12.Ý The first isomer is a
five-carbon chain with three hydrogens bonded to the end carbons and two
hydrogens bonded to the other carbons in the chain.Ý I believe this isomer is called pentane.Ý The second isomer is a four-carbon chain
with the fifth carbon bonded to carbon #2.Ý
In this isomer the end carbons of the four-carbon chain are bonded to
three hydrogens and carbon #3 is bonded to two hydrogens.Ý The second carbon however is bonded to the
fifth carbon and one hydrogen, and finally the fifth carbon is bonded to three
hydrogens.Ý I believe that this isomer
is called 2,methyl butane.Ý The third
isomer is a three-carbon chain with carbons #4 and 5 bonded to the middle
carbon in the chain.Ý The end carbons in
the chain are bonded to three hydrogens and the 4th and 5th carbons are bonded
to the middle carbon and to three hydrogens.Ý
I believe that this isomer may be called 2,2 dimethyl propane.Ý
I came
up with three isomers for the given molecule.Ý
I'm going to try to attach a file to try to better illustrate my
work.Ý However, I'll give you a verbal
description as well(computers. . . you just never know). The first isomer is a
straight chain of 5 carbons (C-C-C-C-C) surrounded by hydrogens (two atoms per
cabon) and one hydrogen on either end of the chain.Ý The second isomer is a cross composed of the five carbon.Ý In this case, the middle carbon is bonded
with the four other carbons, and each outer carbon has three Hydrogen
molecules.Ý The third isomer is very
similar to the first, straight-chain isomer, except one of the carbons is not
in the straight line.Ý It is instead
attached to one of the carbons in the chain, forming a sort of branch off of
the main line.Ý This branched Carbon
will have three hydrogen attached to it, as will both the end carbons.Ý The center carbon (the one attached to three
other carbons), with have only one hydrogen.Ý
The other middle carbon will have only two hydrogens attached to
it.Ý
Ý
2.ÝÝÝÝÝ
ÝÝÝÝÝÝ The signal for a carbon attached
to a nitrogen would be approximately 30 ppm.Ý
This is because nitrogen has a greater elecronegativity than silicon or
carbon, but less than oxygen.Ý Thus, the
signal would fall between that of carbon and oxygen.
The attachment would come at about 20-25 ppm.Ý This is so because the electron density would be more
than a carbon attaching to another carbon and less than a carbon attaching to
an oxygen because the dipole (N) is in between the C and the O so its
electron density would be in the middle as well.Ý Atomic weight has a big deal as the number of electrons affects
the electron density as the carbon attaching to the nitrogen would be somewhete
in between the other two bonding because of the number of electrons in the
valence shell.
I would expect the value for
nitrogen attached to carbon to lie between 15 and 50, most likely around 40 or
so.Ý The explanation for this is based
strongly on differences of electronegativities.ÝÝ Nitrogen is less electronegative than oxygen.Ý Therefore, the dipole moment between the
carbon-oxygen bond is greater than the dipole moment between the
carbon-nitrogen bond.Ý However the dipole
moment between the carbon-carbon bond is less than the dipole moment between
the carbon-nitrogen bond.Ý The electron
density is greater around the more electronegative atom in the bond because it
is pulling harder for the electrons.Ý
Because oxygen is the most electronegative it is pulling the hardest
compared to the carbon it will have the largest value representing the greatest
electron density.Ý Nitrogen is only
slightly less electronegative in comparison to oxygen so it will have only a
slightly smaller electron density, reflected in an only slightly smaller value.
I
believe that it would come somewhere between 15-50ppm.Ý I feel this way because Nitrogen in placed
between Carbon and oxygen on the periodic table.Ý Due to the placement of the electrons on Nitrogen compared to
carbon and oxygen it should fall somewhere between those two limints.Ý I couldn' narrow that scope down any further
though because I don't fully understand this concept yet.
I think
it will be arround 30 or 35 ppm because Nitrogen has one less valence electron than oxygen and
one more valence electron than carbon so it will be in the middle of the two
signals.
Ý
The
signal should be between 30-35 ppm, because that is halfway between the value
for carbon-carbon and carbon-oxygen.Ý
Nitrogen is between carbon and oxygen.Ý
Ý
Between
20 and 25 ppm because nitrogen's polartiy is between the polarity of carbon and
the polarity of oxygen.
I would
imagine the Nitrogen-Carbon bond would have a signal between 15-50.Ý This could be right around 30 or so give or
take 5-7ppm either way.Ý I think that it
would give this type of reading because carbon has less available electrons to
be emitted on the C-13, than Nitrogen and thus a lower signal, but O has more
than C and so gives a higher signal.Ý
Also Nitrogen is in between the two interms of reactivity, so should be
proportionally between them.Ý As for why
silicon has such a low, I think that has to do with its transition metal
catagory, and being in a different period, but I don't know exacty why that
would effect it, because the whole C-13 spec is new to me.
Ý
ÝThe value would range from 20 to 25.Ý This based on the fact that there is 0 ppm
for Silicon, which is in the same period.Ý
The oxygen is two periods over has more electrons in the outer
shell.Ý
Ý
Electronegetivities
increase from left to the right on the periodic table.Ý Since nitrogen is further right than carbon
but to the left of oxygen, the electron density would be greater than 15 ppm,
but less than 50 ppm.Ý (I used my text
and the periodic table to solve this.)
ÝÝÝÝÝÝ A carbon attached to a nitrogen would
occur somewhere between 15ppm
ÝÝÝÝ and 50ppm.Ý This is caused because of the difference between the
ÝÝÝÝ electronegativities.
Ý
THe
signal would be somewhere between 15 and 50, closer to 50 because the
electronegativity of nitrogen is high but not as high as oxygen.
A
carbon attached to nitrogen would come somewhere between 15 ppm and 50 ppm
because the size of
nitrogen is larger than carbon, yet smaller than oxygen.Ý
Ý
A C-N
signal would most likely fall in the range 15ppm to 50 ppm. Nitrogen would
create a larger dipole than C but a smaller dipole than O. The charge on the N
atom is in between the charge on O and the charge on N therefore causing the
mentioned CNMR range.
The ppm values for silicon bonded to
carbon, carbon bonded to carbon, and oxygen bonded to carbon were plotted on a
graph with their respective electronegativities.Ý These three points were connected with a smooth, curved line to
produce a graph.Ý This graph was then
used with nitrogen's electronegativity to estimate what the ppm value for
nitrogen bonded to carbon would be.Ý The
result suggested that a nitrogen bonded to a carbon would have a ppm value near
27.5.
I would expect the nitrogen to be
halfway between the carbon and the oxygen values (~32.5ppm). I arrived at this
by comparing the electronegativity values. Since I know that electronegativity
impacts the way electrons move and that in turn it changes where the electrons
will be I used those values to predict the approximate electron density. The
electronegativity value for nitrogen (3ppm) is halfway between carbon (2.5ppm)
and oxygen (3.5ppm). I checked this answer with Aaron and he seemed to agree.
A
carbon attached to a nitrogen would fall between 15 ppm and 50 ppm.Ý This is because oxygen has a higher
electronegativity, and thus a larger dipole and a larger change in electron
density.Ý Carbon is less
electronegative, and has a smaller change in electron density.Ý Nitrogen falls in between carbon and oxygen
in electronegativity, so it would also fall between them in changes in electron
density.
The
signal for a Carbon-Nitrogen bond would come between 15 and 50 ppm.Ý The electrostatic difference between a
Carbon and Nitrogen bond falls between the values of the electrostatic
difference between a Carbon to Carbon bond and a Carbon to Oxygen bond.Ý Thusly the signal would also fall between
those two signal values.
The
nitrogen would be between 15ppm and 50ppm.Ý
The electron density of nitrogen is larger than carbon yet smaller than
oxygen because of the order of those elements on the periodic table.Ý Carbon comes before nitrogen, which comes
before oxygen.Ý The dipole and electron
density get larger when moving from left to right of the periodic table.
between
15 and 50ppm.
ÝÝ the difference of electronegativity of C
and O is 1.0.Ý That of C and N is 0.5.
and C-C is 0. C-Si is 0.7. At this point, the electron density and the
difference of electronegativity does not seem to have relationship. so I'm really
not sure...
ÝÝ The the bond length C-C is longer than C-N
and C-O. C-N is longer than C-O(from text). since the difference of
electronegativity between them is reverse order( C-C one is smallest). So I
guess i can say that longer distance and weak polar cause smallest electron
density. so the order of electron density would be C-C smallest, C-N,C-O
largest. so the value will be between 15 and 50ppm.
I am
not sure if I can explain with electronegativity especially difference between
C-C is 0.
Since the
signal is dependent on electron density and e- density is
related
to
ÝÝÝÝ electronegativity, carbon and nitrogen
would give a signal
somewhere
between
ÝÝÝÝ 15 and 50 because nitrogen is less
electronegative than O and more
than C.
A
carbon attached to a nitrogen would fall between 15 and 30ppm or between
carbon-carbon and carbon-oxygen.Ý This
is because nitrogenís electronegativity is smaller than oxygenís but a larger
than carbonís.Ý Nitrogenís
electronegativity is closer to that of oxygen than carbon so it would lie
closer to 50 than 15ppm.Ý The difference
in electronegativity between the two atoms determines the strength of the
dipole moments of the atoms.Ý The
greater the difference in electronegativity the greater the dipole moment is
between the two atoms.Ý For example the
atom with the greater electronegativity would attract the electrons with a
stronger force, causing the dipole moment to become more influential on that
atom.Ý From the established data given
in this question, as the difference in electronegativity increases so does the
measure of ppm for that attraction.ÝÝÝÝÝÝÝÝÝÝÝÝ
I
predict that a carbon attached to a Nitrogen would come in at about 30
ppm.Ý Since the position of the signal
was dependent on the electron density around the carbon, I came to this
conclusion by studying the differences in electromagnetivity between the carbon
atom and the other atoms.Ý Silicon is
less electromagnetive than carbon, and perhaps for this reason falls below registering.Ý Oxygen is more electromagnetive than Carbon,
and therefore has a higher reading than that of carbon attached to carbon.Ý Nitrogen has an electromagnetivity of
approximately 3.0; higher than carbon and lower than oxygen.Ý After constructing a rough graph of readings
versus differences in electronegativity, I found that Nitrogen's
electronegativity may put a reading near 30 ppm.Ý
3.Ý ÝÝÝÝÝ
l ñ b
21 ñ c
2 - d
ÝÝÝÝÝÝ The answer is
c.Ý the m/z represents the mass to
charge ratio.Ý The charge in most cases
is 1.Ý therefore the m/z usually
represents the molecular weight of the molecule.ÝÝ The empirical weight is approximately 14g.Ý 56 is the fourth multiple of this number
suggesting that the subscripts be multiplied by four and give us the answer of
C4H8.
4.ÝÝÝÝÝ comments
Any possibility of you going over the stuff in the second half of
chapter two spectroscopy?
The only thing Iím confused
about is in number two.Ý Although I
understand the concept of the electronegativities and dipole moments, Iím
afraid I donít have an explanation for the silicon-carbon bond value being 0,
or the fact why carbon-carbon would even have a dipole moment.ÝÝ I am fairly confident that my explanation
is valid, but I cannot account for that.Ý
Acknowledgements:Ý
Assistance
from Becca Fredrick, Todd Young, Katie Palof, and Jen Fraifogle.
I
really hope that you arent grading this warmups very hard becuse this kind of
learning doesn't work for me very well.Ý
I need to talk to someone who knows how to do these problems for sure,
because if I just try to beat my way through to the correct answer I end up
second guessing myself.Ý This uneasyness
about my ability to find the correct answer usually continues through the time
it has been explained to me the correct way and I end up being too unsure of my
own abilities.
I am
very unclear on a bunch of concepts and the spec reading seemed to be over my
head in a lot of places. The ring structures on pg 3 of the spec book confused
me as to how they appled the 2n +2 formula to them and arrived at the right
answers in constructing the carbon ring sequence.Ý Also does the 2n + 2 give the # of hydrogens?.Ý What is the base peak, and how does that
help us understand the others?Ý And what
are the M+, R+, B+, ect labels? What do they stand for, mean, relate to?Ý I was just very lost at the end of chapter 2
of the reading and I had difficulty straightening out what was useful and what
was just above me.
Ý But hopefully with time.
ÝÝÝ Thanks and as soon as we can get some
clearity on these i will be greatly apprieciative.
I don't
understand what resonance structures are on page 16 of the text.
I also
don't understand the counting method/ not crossing lines thing (page 3 of
Spectroscopy book) used to determine degrees of seperation.
I an
not sure that I named the isomers correctly in the first question but I hope
that I described them well enough for you to understand them.Ý Also, in the second question I understand
why nitrogen would fall where it does but I do not understand how the measurements
of ppm relate to what is being measured in the experiment.Ý For example, why does the carbon-carbon bond
come out 15 ppm, when carbon-carbon is equal?Ý
Acknowledgements:Ý Jen Fraifogl, Lauren Bell, Todd Young, and
Becca Fredrick.
Ý
I
really hope we can go over question number two.Ý I spent a great deal of time trying to get my brain to unwrap
that one!Ý Also, will we need to know
how to determine the vector magnitude of dipole moments?Ý