Number of results: 144
ochem
For a Grignard reaction, if you start with 3.97 mL of pure bromobenzene and 0.733 g of 1-phenylethanone, what is the theoretical yield of 1,1-diphenylethanol? Please help.
Monday, February 27, 2012 at 1:31am by ochem
OChem
You might try here for help: http://www.google.com/search?q=OChem+tutorial&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a Sra
Sunday, May 17, 2009 at 3:31pm by SraJMcGin
chem102
I meant to leave this link in the original response but forgot. http://www.utdallas.edu/~scortes/ochem/OChem1_Lecture/Class_Materials/07_org_nomenclature1.pdf
Saturday, July 24, 2010 at 4:17am by DrBob222
ochem
thanks!
Monday, February 27, 2012 at 1:31am by ochem
ochem
Yes.
Tuesday, April 14, 2009 at 6:53pm by DrBob222
OChem
all of them
Wednesday, October 12, 2011 at 3:44am by john
OCHEM
hhdgfhdgdg
Tuesday, June 1, 2010 at 9:34pm by 21456
OCHEM
hhdgfhdgdg
Tuesday, June 1, 2010 at 9:34pm by Anonymous
ochem
thank you so much
Saturday, November 13, 2010 at 2:42am by natalie
OChem
R-S= %ee I think
Wednesday, November 2, 2011 at 7:35pm by Anonymous
Ochem Lab
Thanks For Nothing :)
Sunday, October 24, 2010 at 6:25pm by Adam
Ochem
mega n00b
Wednesday, February 1, 2012 at 12:19am by UCI Goddess
Ochem
ur a noob
Wednesday, February 1, 2012 at 12:19am by UCI God
Ochem
+ on one end and - on the other.
Tuesday, October 18, 2011 at 4:14am by DrBob222
OChem
just kidding, idk
Wednesday, October 12, 2011 at 3:44am by john
Ochem Lab
good luck
Sunday, October 24, 2010 at 6:25pm by Amy
ochem
how to determine equivalent hyfrogens in hnmr?
Saturday, December 3, 2011 at 6:05pm by tim
OChem
hahaha = your moms ass mofo
Wednesday, October 12, 2011 at 3:44am by Rupert
OChem
hey have u gotten the answer yet?
Thursday, October 20, 2011 at 1:26am by Anonymous
OChem
hey have u gotten the answer yet?
Thursday, October 20, 2011 at 1:26am by Anonymous
ochem
1) solubility in cold ethanol is higher than expected.
Wednesday, October 6, 2010 at 3:44am by bobpursley
Ochem Lab
This has been answered recently.
Sunday, February 8, 2009 at 11:55pm by Dr Russ
OChem
%ee = (+81.5/+125.5) x 100% it was in the techniques book! :)
Wednesday, November 2, 2011 at 7:35pm by Anonymous
ochem
at room temperature is caffeine soluble in water or dichloromethane
Thursday, October 6, 2011 at 11:36pm by joe
ochem
NaOCl+ CH3COOH-> HOCl+ CH3COO+ Na
Thursday, January 29, 2009 at 9:00pm by Anonymous
Ochem
what about the Q. acetaldehyde impurity arise fermentation? Dr. Bob
Thursday, October 12, 2006 at 10:35am by L
Chemistry
Do we not need to take the solubility into account in the calculation?
Sunday, August 12, 2012 at 12:44am by Ochem is hard
OChem
I usually pour the solvent in first; however, I don't know that it makes any difference.
Wednesday, June 8, 2011 at 5:53pm by DrBob222
ochem
What's an equation of the hydrolysis of one ester group in tannins by CaCO3?
Friday, April 16, 2010 at 10:30pm by Rachel
ochem
What's an equation of the hydrolysis of one ester group in tannins by CaCO3?
Thursday, April 15, 2010 at 12:41am by kim
ochem
Start with the balanced equation? Have you figured that out yet?
Thursday, January 29, 2009 at 9:00pm by bobpursley
Ochem
Give two reasons why the crude product in most reactions is not pure.
Saturday, March 10, 2012 at 12:46am by chi
ochem
In a sn2 reaction why do we need sp3 hybrid orbital and not sp2 for the substrate
Sunday, January 29, 2012 at 7:16pm by lou
ochem
is cis-1,2-dimethylcyclohexane a conformational isomer of trans-1,2-dimethylcycloehexane? Please explain.
Thursday, October 13, 2011 at 9:38pm by sammy
ochem
A. Too soluble in ethanol. B. The sample was VERY crude (not much of the compound to start with).
Wednesday, October 6, 2010 at 3:44am by DrBob222
Ochem Lab
See Saturday, February 7, 2009 at 10:59am
Sunday, February 8, 2009 at 11:55pm by Dr Russ
Ochem
4-chlorophenolate will act as a GOOD NUCLEOPHILE and and take place of the Chlorine on the chloroacetic acid.
Saturday, January 15, 2011 at 3:45pm by Anonymous
Ochem
Phenacetin has the structure shown below. Write an equation for its preparation starting from 4-ethoxyaniline.
Saturday, March 10, 2012 at 12:45am by chi
OChem
Typo: What intermolecular forces are important in the binding of molecules to the ADSORBENT in ADSORPTION chromatography?
Wednesday, October 12, 2011 at 3:44am by Allison
OCHEM
Pg 201 of techniques under the subtitle "Poor Separation of a Mixture" should answer #2 for you.
Tuesday, December 22, 2009 at 10:22pm by Chris
Ochem
If 1.43 g of 4-ehoxyaniline and an excess of the acylating agent were used to prepare phencetin, what is the theoretical yield of product?
Saturday, March 10, 2012 at 12:54am by chi
Ochem
wel i just wanted to know the final answer or at least the equation. Here is my work V= (.234)(.082)(298)/760
Thursday, October 12, 2006 at 10:35am by Ben
Ochem Lab
Suggest an appropriate reducing reagents for the following substrates and predict the reaction:(1) 2-hexanone, (2)ethyl 4-nitrobenzoate, (3) hexanal
Sunday, February 8, 2009 at 11:55pm by sady
ochem
Why is that that a third order alkyl halide reacts faster in SN1 mechanism? Why is it the opposite for SN2? (is it just steric hindrance? )
Monday, November 24, 2008 at 10:11pm by Dora
OChem
john tsai you're a chink dont think that i dont know you
Wednesday, October 12, 2011 at 3:44am by Allison
ochem
A sample of Limonene has a specific rotation of +76.9. What is the % ee and molecular composition of this sample?
Saturday, November 13, 2010 at 2:38am by bjisa
OChem
Thank you for the formula I was wondering for the answer I got 0.778 ml bleach. I was wondering if that was correct?
Tuesday, December 22, 2009 at 12:36am by Sarah
ochem
One possible reason could be that the compound to be isolated is too soluble in water or too soluble in EtOH.
Friday, January 23, 2009 at 12:43am by DrBob222
OCHEM
I have the same question and it doesn't have any impurities.
Sunday, August 12, 2012 at 12:43am by MAry
OChem
or +125.6. idk which one is the one in your problem.
Wednesday, November 2, 2011 at 7:35pm by Anonymous
ochem
propose structual formulas for pheophytin a and pheophytin b
Monday, November 24, 2008 at 9:21pm by anna
Ochem
What volume of 6.83% (wt./vol.) NaOCl solution is required to oxidize 223 mg of 9-fluorenol to 9-fluorenone? Please help me set this up!
Wednesday, February 1, 2012 at 3:45am by Darby
OCHEM
When 2-methyl-2-butene is bubbled into dilute sulfuric acid at room temperature, it appears to dissolve. What new substance has been formed?
Thursday, January 7, 2010 at 6:59pm by josh
UCI OCHEM
You are a bad bad person. LOLWAT. Just stumbled on this looking for the answer, hahaha!
Wednesday, January 30, 2013 at 5:24am by Professor AntEater
OChem
For Extraction using a separatory funnel, what is poured into the funnel first the solution that is to be extracted or the solvent?
Wednesday, June 8, 2011 at 5:53pm by Jasmin
Ochem
What volume of 6.43% (wt.vol.) NaOCl solution is required to oxidize 221 mg of 9-fluorenol to 9-fluorenone? I'm not to sure of where to start with this problem. Please help!
Wednesday, February 1, 2012 at 12:19am by Jessica
OChem
Why would diethylammonium chloride insoluble in ether? Is the only reason why the salt is insoluble because of polarity, or are there other reasons why? Please explain.
Wednesday, April 27, 2011 at 3:36am by anon
Ochem
By looking at the chemical structures of acetaminophen, aspirin, caffeine, ibuprofen, and naproxin sodium, how are you able to determine the relative polarity of each? Does it have something to do with the symmetry of the structure? Please help!
Tuesday, October 18, 2011 at 4:14am by Luis
Ochem
how many grams of NaOCl are in 12.14 mL of a 6.65% (wt./vol.) NaOCl solution? Please help me set this up... I have no idea what to do.
Wednesday, February 1, 2012 at 3:46am by Seerat
ochem
Give the reaction products of sodium borohydride (followed by water addition at the end of the reaction) with the following compounds: a) Acetone b) m-nitroacetophenone c) 3-buten-2-one
Tuesday, May 7, 2013 at 11:32pm by ang
OCHEM DR BOB PLEASE HELP!!!!!!!!!1
Why is it possible to use melting point to distinguish the different stereochemistry of the products? (Hint: what is the relationship of the different stereoisomers of the product?)
Wednesday, August 15, 2012 at 2:11pm by JEN
ochem
bromide is a better nucleophile toward the intermediate bromonium ion than ethanol. what product would be obtained if ethanol did carry out this nucleophilic attack?
Saturday, November 29, 2008 at 3:54pm by ana
Ochem
Give the products (if any) expected from the treatment of the following compounds with ozone followed by aqueous hydrogen peroxide. Do not include any byproducts. 1) 2-methyl-2-pentene 2) cyclooctene Please help! I'm not sure on where to start with this problem.
Wednesday, February 8, 2012 at 1:41am by Lucy
ochem
Which of the cyclohexane conformation is more stable? (chair of boat) What factors cause the observed differences in strain energy between the two conformations of the cyclohexane studied above?
Saturday, March 24, 2012 at 3:37pm by cn
Chemistry/Ochem
1 to 2 degrees celsius per minute. If it is too fast, you can overestimate the melting point, and if you are trying to determine the range, the range wil be narrower then it would be at a slow temperature.
Thursday, January 24, 2013 at 9:55pm by Devron
Ochem
Diethyl ether is used as a solvent for the reaction of diethylamine with m-toluoyl chloride. Why is a solvent necessary for this reaction?
Tuesday, April 26, 2011 at 2:57am by anon
Ochem
In the reaction between p-aminophenol and acetic anhydride to form acetaminophen, what was the purpose of adding water to the reaction mixture? There are a couple of possible answers, and this requires a detailed explanation for credit. thanks!
Saturday, March 10, 2012 at 12:50am by chi
ochem
No, because you CANNOT convert cis-1,2-dimethylcyclohexane into the trans isomer by rotation about the double bond since the double bond does not rotate.
Thursday, October 13, 2011 at 9:38pm by DrBob222
ochem
We can't draw structures on the board but here is what I could find on the web. I don't see any structures but there is a lengthy description. Perhaps you already know all of this; perhaps not. Use it if you can.
Monday, November 24, 2008 at 9:21pm by DrBob222
OChem
hahah lol, my names not even john, i know you dont know me, because i dont know you hahahahahaha
Wednesday, October 12, 2011 at 3:44am by john
ochem
After reacting racemic phenylethylamine with R,R-tartaric acid, several of our class samples contained needle-like crystals instead of prismatic crystals. What did this indicate about the success of the separation?
Monday, April 2, 2012 at 11:28pm by OH
OCHEM
How would the 1H NMR spectrum of 1,3-dibenzoylpropane differ from that of the product, trans-1,2-dibenzoylcyclopropane? would the chemical shifts of the protons alpha and beta to the carbonyl groups be appreciably different? explain.
Tuesday, June 1, 2010 at 9:34pm by kris
OChem
I think if you draw out the fluorenol and fluorenone the H atoms in your equation will not balance. Try 9-fluorenol + NaOCl ==> 9-fluorenone + NaCl + H2O
Tuesday, December 22, 2009 at 12:36am by Dr Russ
OChem
Anhydrous conditions are vital for a successful Grignard synthesis. To demonstrate this point calculate the mass of the water it would take to destroy the phenylmagnesium bromide you will synthesize. What is he volume of this amount of water? -How exactly do you do this?
Monday, March 2, 2009 at 11:27pm by Kristy
Ochem
1. inclusion of starting material 2. inclusion of side reaction material
Saturday, March 10, 2012 at 12:46am by DrBob222
ochem
Calculate the amount (volume) of 5.25% (wt./vol.) NaOCl solution (commercial bleach) required to oxidize 100 mg of 9-fluorenol to 9-fluorenone. Whenever appropriate, use balanced chemical equations as a part of your calculation.
Thursday, January 29, 2009 at 9:00pm by steve
OChem
lewis acid-base because of the solvent ur using / dipole-dipole because stationary phase is polar / hydrogen boding because of silica gel bet the mofo is a chink too lmfao u go girl allison
Wednesday, October 12, 2011 at 3:44am by Rupert
ochem lab
this deals with TLC chromatography: if 2 compounds have same Rf under identical conditions, does it show that they have identical structures? i think it does. but im not sure why. thanks mucho.
Friday, November 2, 2007 at 4:42pm by christine
ochem
If you recrystallize a compound with a 1/2 ethanol/water mixture and water remains in the compound after recrystallization, would that change the melting range of the pure compound?
Tuesday, April 14, 2009 at 6:53pm by bee
ochem
Predict a reasonable melting point of a mixture prepared by combining 25mg of biphenyl (mp=70-71C) with 75mg of acetyl salicylic acid (mp=138-140C). Answer should have temps in it.
Thursday, September 15, 2011 at 12:48am by katie
Ochem
For the reaction between chloroacetic acid and 4-chlorophenolate to synthesize 4-chlorophenoxyacetic acid, why is this reaction a sn2 reaction?
Saturday, January 15, 2011 at 3:45pm by anon
Ochem
Identify the following compound from its IR and proton NMR spectra. C6H10O: NMR: 3.31 (3H, s); 2.41 (1H, s); 1.43 (6H, s) IR: 2110, 3300 cm^-1 (sharp)
Wednesday, February 15, 2012 at 5:10pm by Suzan
Ochem
balace equation for the follwing 1. Li + O2 2. K + O2 3. Na + O2 4. RbCl + Na
Wednesday, April 22, 2009 at 1:54pm by Lety
OCHEM
Does the mixture contain impurities as well as fluorene and benzoic acid? Do you know the solubility of fluorene and benzoic acid. Are you to assume 100% yield?
Sunday, August 12, 2012 at 12:43am by DrBob222
OChem
1. Why does not fluorene dissolve in 1.5M sodium hydroxide solution? 2. What experimental difficulty would you encounter if you had neclected to include a drying step before evaporating the ether solution of the neutral organic compound (fluorene)?
Tuesday, November 4, 2008 at 4:26pm by James
OChem
Anhydrous conditions are vital for a successful Grignard synthesis. To demonstrate this point, calculate the mass of water it would take to destroy the phenylmagnesium bromide that synthesized from 0.48 mL of bromobenzene and 112.5 mg of magnesium. What is the volume of this ...
Sunday, May 17, 2009 at 3:31pm by bee
ochem
Which of the trans-1,4-dimethylcyclohexane is more stable? ("di-axial" or the "di-equitorial") What factors cause the observed differences in strain energy between the two conformations of trans-1,4-dimethylcyclohexane studied above?
Saturday, March 24, 2012 at 3:39pm by cn
Ochem Lab
why is it important to spot samples directly on the marks made on the TLC plate? This is for Thin Layer Chromotography. Is this important so that the solvents move directly up the plate and can be identifies easily? Thanks
Sunday, October 24, 2010 at 6:25pm by Adam
OCHEM
Write the mechanism for (E)-2-5-dimethyl-hex-3-ene and bromine? Assign the R, S configuration for each of the products and determine the stereochemical relationship of each set of products. I think the products will be trans but I am not quite sure how the mechanism work. Any ...
Monday, February 1, 2010 at 6:56pm by Rebecca
Ochem
Which Alkene is capable of stereoisomerism: 1-pentene, 2-methyl-1-pentene, 2-methyl-2-pentene, 2-pentene, or 2,3-dimethyl-2-butene?
Saturday, July 21, 2012 at 6:16pm by Michele
ochem
A student dissolved 30 mg of a crude unknown in 2 ml of 95% ethanol at room temperature. After chilling in an ice bath and washing crystal with small amount of ice-cold ethanol, she recovered 5mg. Why was the recovery so low?
Wednesday, October 6, 2010 at 3:44am by Anonymous
ochem lab
What is the expected observed rotation of a 9.1 x 10-5 M solution of compound X? Note: compound X has a specific rotation of [α]D20 = -49o and a molecular weight of 235.2 g/mol. In addition, the path length of the cell used to take the polarimetry measurement was 5.0 cm.
Monday, April 2, 2012 at 11:28pm by cn
OChem
Could someone explain these two reaction mechanisms (I know they are substitution): 1) 1-propanol reacted with H2SO4 and NaBr 2) 2-pentanol reacted with H2SO4 and NaBr does the carbocation rearrange for the second reaction? thanks for the help!
Tuesday, April 21, 2009 at 10:13pm by bee
OCHem
The amount of methylcycloheane with the substituent in the equatorial orientation at room temperature (25C) would be The Gibbs free energy for axial methyl to equatorial methyl is -7.28Kj/mol (the universal gas constant is 8.314 j/deg-mol). I cant remember how to solve this...
Friday, December 10, 2010 at 1:15pm by Alex
Chemistry/ OChem
Read the web site I highlighted in response below and see if that gives you some ideas. The trick is to look at the components to be separated and make an educated guess about their polarity, then match that to a solvent that will move the components at different speeds up the...
Thursday, October 9, 2008 at 3:22pm by DrBob222
Ochem
I would try setting it up as a proportion. The percentage just means that there are 6.65 grams of NaOCl per 100 grams. Therefore, set up the problem of (6.65/100)=(x/12.14)
Wednesday, February 1, 2012 at 3:46am by Shannon
OChem
A mixture of acetone and ethyl acetate of unknown ratio begins to boil at 65 degrees celcius (760 torr). What is the composition of this binary mixture in terms of the mole fraction of acetone and that of ethyl acetate?
Saturday, September 25, 2010 at 9:30pm by doug
OChem
I have answered a very similar question before quite recently. 1) is likely to be SN2 (it will depend on the conditions) 2) will be predominantly SN1 which means that there could be competing rearrangement of the +ion and competing elimination. There is a good description of ...
Tuesday, April 21, 2009 at 10:13pm by Dr Russ
ochem
this test the concept of reacting metal hydride with the ketone. metal hydride reduces ketones. ketones are reduced to secondary alcohol adding water with the product (alcohol) can form carboxylic acid.. that's far as i remembered.
Tuesday, May 7, 2013 at 11:32pm by bonjo
OChem
btw the answer is Hydrogen bonding Dipole-dipole interactions Lewis acid-base interactions don't let that clown troll john mofo fool you. mofo doesn't have a brain and tries to be a troll lmfao pisses me off
Wednesday, October 12, 2011 at 3:44am by Rupert
For Further Reading
