Heteroatomic-molecules

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Question:I've been doing this problem for the past half hour or so as practice, and I seem to be having a little difficulty. Basically, I'm supposed to analyze the data and come up with a conclusion based on the data. I truly don't want the answerer to just splurge the answer out without detail. I rather be given help in terms of explaining the correct way of doing it. I've provided a couple of observations of what I believe it is on the image. http://img56.imageshack.us/my.php?image=spectroanalysisft7.jpg * The arial fonted notes are my observations. Because of only one monochloro product, I assume that the final structure will be one where regardless of which hydrogen is removed, will always yield that same product. So perhaps the product is 1-chloromethane (or similar alkane derivative)? It seems this is an alkane undergoing the reaction, as this is a radical reaction. This would explain the lack of a terminal alkene/alkyne marker on the IR Spectrum, and as such show sp3 carbon bonding. There seems to be no sp2 or sp C-H bonding as the spikes do not go beyond 3000 as seen in sp2 and sp C-H bonds. I don't know how to fully interpret the MS data, so I would appreciate help with that as well. Hopefully someone here could lend me some assistance in analyzing this, and not merely just give an unexplained answer. I truly wish to understand this, and have put in the effort to understand it. Anyways, thanks to everyone who contributes!

Answers:Something's bugging me about your mass spectrum. Chlorine exists as two isotopes, Cl-35 and Cl-37, and their respective natural abundance ratio is 75:24, or 3:1. So you should see two fragment peaks with that abudance ratio, two amu apart (lower amu peak should be larger). It's strange, because I don't see anything like that in your mass spectrum there. The 39/41 pair has a completely wrong abundance ratio. There should be two molecular ion peaks with the same relationship, but there aren't. Here's an example of what I'm talking about: http://webbook.nist.gov/cgi/cbook.cgi?ID=C109693&Units=SI&Mask=200#Mass-Spec You're right that the highest peak in the mass spectrum is usually the molecular ion, i.e., that's usually the molar mass of the compound. If we assume a molar mass of 71amu, the chlorine will take up 35amu of that, leaving 36amu more for C and H. But here's where I get stumped. There are no viable combinations of C and H that add up to 36amu - C2H12 violates the 2n+2 rule for maximum number of hydrogens per carbon. I can only conclude that you must have another heteroatom in there besides chlorine. But the IR indicates no oxygen, and I don't see any evidence of nitrogen, either. Fluorine might be a candidate because it only shows up in the fingerprint region (600-800) but F is 19amu, and that leaves 17amu for C and H. CH5ClF is not a viable molecule. Sorry I can't be of more help! Do you have a TA you could ask about this? The mass spectrum really doesn't look like a chlorohydrocarbon to me.

Question:1.Classify each of the following as a physical or chemical change, and give at least one observation, fact, or reason to support your answer. a. An inflated balloon gets larger when heated. b. A baking cake burns. c. A bottle of milk sours. d. A stretched rubber band breaks. aa. A stick is broken into 2 pieces. bb. A candle burns. cc. Rock salt is crushed with a hammer. dd. Tree leaves change color in autumn. 2.Classify each of the following properties as a physical or chemical. Explain your reasoning in each case. A. Mercury metal is a liquid at room temperature. B. Sodium metal reacts vigorously with water. C. Water freezes at 0 degrees Celsius. D. Gold does not rust. E. Chlorophyll molecules are green in color. 3.Succinic acid, a white solid that melts at 182 degrees celsius, is heated gently, and a gas is given off. After the gas evolution stops, a white solid remains that melts at a temperature different from 182 degrees celsius. A. Have the succcinic acid molecules been changed by the process? Explain your answer. B. Is the white solid that remains after heating still succinic acid? Explain your answer. C. In terms of the number of atoms contained, how do you think the size of the succinic acid molecules compares with the size of the molecules of the white solid produced by this process? Explain your answer. D. Classify molecules of succinic acid by using the term homoatomic or heteroatomic. Expalin your answer. 4.Classify each pure substance represented below by a capital letter as an element or compound. Indicate when such a classification cannot be made, and explain why. A. Two elements when mixed combine to form only substance L. B. An element and a compound when mixed form substances M and Q. C. Substance X is not changed by heating it. 5.Classify each of the following as homogenous or heterogeneous: A. A pure gold chain. B. Liquid eyedrops. C. Chunky peanut butter. D. A slice of watermelon. E. Cooking oil. F. Italian salad dressing. G. Window glass. aa. Muddy flood water. bb. Gelatin dessert. cc. Normal urine. dd. Smog-filled air. ee. An apple ff. Mouthwash gg. Petroleum jelly 6.The following pairs of substances represent heterogenous mixtures. For each pair, describe the steps you would follow to seperate the components and collect them. A. Wood sawdust and sand. B. Sugar and sand. C. Iron filings and sand. D. Sand soaked with oil. 7.A chemist is brought a small solid figurine. The owner want to know if is is made of silver but doesn't want it damaged during the analysis. The chemist decides to determine the density, knowing that silver has a density of 10.5g/mL. The figurine is put into a graduated cylinder that contains 32.6mL of water. The reading while the figurine is in water is 60.1 mL. The mass of the figurine is 240.8g. Is the fugurine made of silver? Expalin your reasoning.

Answers:wow, this is one long assignment. i think you should do it on your own so as to test whether you have learned and understood your lessons at school.. look, i really ADORE chemistry and math but i"m afraid i can't help you.. do it on your own.. and after you do it, i'm sure you'll be happy to realize that you did something using your own dexterity and dilligence. good luck! :)

Question:1.Classify each of the following as a physical or chemical change, and give at least one observation, fact, or reason to support your answer. a. An inflated balloon gets larger when heated. b. A baking cake burns. c. A bottle of milk sours. d. A stretched rubber band breaks. aa. A stick is broken into 2 pieces. bb. A candle burns. cc. Rock salt is crushed with a hammer. dd. Tree leaves change color in autumn. 2.Classify each of the following properties as a physical or chemical. Explain your reasoning in each case. A. Mercury metal is a liquid at room temperature. B. Sodium metal reacts vigorously with water. C. Water freezes at 0 degrees Celsius. D. Gold does not rust. E. Chlorophyll molecules are green in color. 3.Succinic acid, a white solid that melts at 182 degrees celsius, is heated gently, and a gas is given off. After the gas evolution stops, a white solid remains that melts at a temperature different from 182 degrees celsius. A. Have the succcinic acid molecules been changed by the process? Explain your answer. B. Is the white solid that remains after heating still succinic acid? Explain your answer. C. In terms of the number of atoms contained, how do you think the size of the succinic acid molecules compares with the size of the molecules of the white solid produced by this process? Explain your answer. D. Classify molecules of succinic acid by using the term homoatomic or heteroatomic. Expalin your answer. 4.Classify each pure substance represented below by a capital letter as an element or compound. Indicate when such a classification cannot be made, and explain why. A. Two elements when mixed combine to form only substance L. B. An element and a compound when mixed form substances M and Q. C. Substance X is not changed by heating it. 5.Classify each of the following as homogenous or heterogeneous: A. A pure gold chain. B. Liquid eyedrops. C. Chunky peanut butter. D. A slice of watermelon. E. Cooking oil. F. Italian salad dressing. G. Window glass. aa. Muddy flood water. bb. Gelatin dessert. cc. Normal urine. dd. Smog-filled air. ee. An apple ff. Mouthwash gg. Petroleum jelly 6.The following pairs of substances represent heterogenous mixtures. For each pair, describe the steps you would follow to seperate the components and collect them. A. Wood sawdust and sand. B. Sugar and sand. C. Iron filings and sand. D. Sand soaked with oil. 7.A chemist is brought a small solid figurine. The owner want to know if is is made of silver but doesn't want it damaged during the analysis. The chemist decides to determine the density, knowing that silver has a density of 10.5g/mL. The figurine is put into a graduated cylinder that contains 32.6mL of water. The reading while the figurine is in water is 60.1 mL. The mass of the figurine is 240.8g. Is the fugurine made of silver? Expalin your reasoning.

Answers:I dont want to do ALL your homework, but heres some pointers 1 and 2)any kind of chemical reaction is a chemical change, (burning, etc). anything else is generally physical (solubility, strength, boiling, freezing) 3) You can tell a chemical reaction has indeed occured, since its properties has changed, (color, melting point ), so its molecules has changed. And since its lost some matter in the form of gas, it would generally be smaller. However, it may have reacted with oxygen to get bigger 4) a)compound. a compound is is formed from a number of elements. since 2 substances form 1, the product has to have more than 1 different element in it b)at least one them is a compound. c)hard to say. gold, for example doesnt change much when heating it, but so doesnt something like aluminum oxide (gold's an element, alumina is a compound) 5)homogenous = things that are dissolved, or pure substances. heterogenous = you can see lumps in it, essentially something like an apple or chunky peanut butter is obviously hetergenous, but so is something like smog filled air, since smoke consists of small solid particles. 6) a) wood floats b) sugar dissolves in water c)iron is magnetic d)oil floats in water, sand sinks. use your logic here 7)find the difference in volume (in mL) in the water. thats the volume of the statue. the mass is given density is mass/volume. is it the same density as silver?


From Youtube

Dabblings in PyMOL

This is my first movie built from rendered molecular structures using PyMOL (created in Feb 2007)...and also really my first excursion into 3D protein structures generally. This was part of an assignment for my bioinformatics class (InBio 465) at BYU. I was a little frustrated with the poor documentation on PyMOL's movie scripting capabilities, so I wrote a script that calculated the frame-by-frame between zoom, translation, and rotation "key frames." First, I downloaded protein structure data from www.rcsb.org/pdb/ which looked cool (the POPE membrane I found elsewhere on the net, and I duplicated in twice to create the semi-continuous layer you see in the first scene). Using PyMOL's Python interface, I positioned molecules into key moments and used my script to generate a series of transitional frames, with an output png file made at each step. Finally, I added music and put all the frames together using VideoMach (not the greatest, but it was easy and fast). The scene where the structure attaches itself to the DNA helix is correct, as I took it directly from the PDB file. The heteroatom shooting off the MDM2/p53 complex is a complete falsification for effect. I didn't have any proteins I was intimately familiar with (yet...I'm still an undergrad), so I took some artistic license on that one. Enjoy. -Elliott

Identifying Polar Covalent Bonds in Organic Molecules

This video describes the process of identifying various types of bonds based on polarity and bond order (single, double, triple). Heteroatoms, any atoms other than hydrogen and carbon, are excellent markers to look for when locating polar covalent bonds due to their higher electronegativities compared to carbon.


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