All Matches

Solution Library

Expert Answer

Textbooks

Search Textbook questions, tutors and Books

Oops, something went wrong!

Change your search query and then try again

Result Not Found

Books FREE
Tutors
Study Help
Hire a Tutor
AI Study Help New

Search
Sign In
Register

study help
chemistry
organic chemistry

Questions and Answers of Organic Chemistry

Indicate the number of signals and the multiplicity of each signal in the 1H NMR spectrum of each of the following compounds: a. ICH2CH2CH2Br b. ClCH2CH2CH2Cl c. ICH2CH2CHBr2
Explain why the signal for the protons identified as Ha in Figure 14.19 appears at the lowest frequency and the signal for the protons identified as Hc appears at the highest frequency.
How could 1H NMR spectra distinguish the following compounds?
How would the 1H NMR spectra for the four compounds with molecular formula C3H6Br2 differ?
Identify each compound from its molecular formula and 1H NMR its spectrum:a. C9H12b. C5H10O c. C9H10O2
Predict the splitting patterns for the signals given by each of the compounds in Problem 3.a. CH3CH2CH2CH3b. BrCH2CH2Brc. CH2==CHCld.e. f. g. h. i. j. k. l. m. n. o.
Identify the following compounds. (Relative integrals are given from left to right across the spectrum.) a. The 1H NMR spectrum of a compound with molecular formula C4H10O2 has two singlets with an
Describe the 1H NMR spectrum you would expect for each of the following compounds, using relative chemical shifts rather than absolute chemical shifts:a. BrCH2CH2Brb. CH3OCH2CH2CH2Brc.d. e. f. g.
Why is there no coupling between Ha and Hc or between Hb and Hc in cis-or trans-3- chloropropenoic acid?
Identify the compound with molecular formula C8H10O that gives the IR and 1H NMR spectra shown in Figure 14.23.
Draw a splitting diagram for Hb, wherea. Jba = 12 Hz and Jbc = 6 Hzb. Jba = 12 Hz and Jbc = 12 Hz
Explain why the chemical shift of the OH proton of a carboxylic acid is at a higher frequency than the chemical shift of an OH proton of an alcohol.
Which would show the signal for the OH proton at a greater chemical shift, the 1H NMR spectrum of pure ethanol or the NMR spectrum of ethanol dissolved in CH2Cl2?
Propose a mechanism for base-catalyzed proton exchange.
Identify the compound with molecular formula C3H7NO responsible for the 1H NMR spectrum in Figure 14.29.
Answer the following questions for each of the compounds:a. How many signals are in the 13C NMR spectrum?b. Which signal is at the lowest frequency?1. CH3CH2CH2Br2. (CH3)2C==CH23. CH3CH2OCH34.
Describe the proton-coupled 13C NMR spectrum for compounds 1, 3, and 5 in Problem 36, showing relative values (not absolute values) of chemical shifts.1. CH3CH2CH2Br3. CH3CH2OCH35.
How can 1,2-, 1,3-, and 1,4-dinitrobenzene be distinguished by a. 1H NMR spectroscopy? b. 13C NMR spectroscopy?
Identify each compound in Figure 14.35 from its molecular formula and its 13C NMR spectrum.a. C11H22Ob. C8H9Br c. C6H10O QUESTION CONTINUE TO NEXT PAGE d. C6H12
Identify pairs of coupled protons in 2-methyl-3-pentanone, using the COSY spectrum in Figure 14.39.
How many signals are produced by each of the following compounds in itsa. 1H NMR spectrum?b. 13C NMR spectrum?1.2. 3. 4. 5. 6.
Draw a splitting diagram for the Hb proton and indicate its multiplicity ifa. Jba = Jbcb. Jba = 2Jbc
Label each set of chemically equivalent protons, using a for the set that will be at the lowest frequency (farthest upfield) in the 1H NMR spectrum, b for the next, etc. Indicate the multiplicity of
Match each of the 1H NMR spectra on page 575 with one of the following compounds:a. b. c.
Determine the ratios of the chemically nonequivalent protons in a compound if the steps of the integration curves measure 40.5, 27, 13, and 118 mm, from left to right across the spectrum. Give the
How could 1H NMR distinguish between the compounds in each of the following pairs?a. CH3CH2CH2OCH3 and CH3CH2OCH2CH3b. BrCH2CH2CH2Br and BrCH2CH2CH2NO2c.d. e. f. g. h. i.
Answer the following questions: a. What is the relationship between chemical shift in ppm and operating frequency? b. What is the relationship between chemical shift in hertz and operating
The 1H NMR spectra of three isomers with molecular formula C4H9Br are shown here. Which isomer produces which spectrum?a.b. c.
Identify each of the following compounds from the NMR data and molecular formula. The number of hydrogens responsible for each signal is shown in parentheses. a. C4H8Br2 1.97 ppm (6) singlet 3.89 ppm
There are three isomeric dichlorocyclopropanes. Their 1H NMR spectra show one signal for isomer 1, two signals for isomer 2, and three signals for isomer 3. Draw the structures of isomers 1, 2, and 3.
Identify the compound with molecular formula C7H14O that gives the following proton-coupled 13C NMR spectrum.
Compound A, with molecular formula C4H9Cl, shows two signals in its 13C NMR spectrum. Compound B, an isomer of compound A, shows four signals, and in the proton-coupled mode, the signal farthest
The 1H NMR spectra of three isomers with molecular formula C7H14O are shown here. Which isomer produces which spectrum?a.b. c. QUESTION CONTINUE TO NEXT PAGE
Would it be better to use 1H NMR or 13C NMR to distinguish among 1-butene, cis-2-butene, and 2 methylpropene? Explain your answer.
Determine the structure of each of the following unknown compounds based on its molecular formula and its IR and 1H NMR spectra.a. C5H12Ob. C6H12O2 c. C4H7ClO2 d. C4H8O2
There are four esters with molecular formula C4H8O2.How could they be distinguished by 1H NMR?
An alkyl halide reacts with an alkoxide ion to form a compound whose 1H NMR spectrum is shown here. Identify the alkyl halide and the alkoxide ion.
Determine the structure of each of the following compounds based on its molecular formula and its 13C NMR spectrum.a. C4H10Ob. C6H12O
The 1H NMR spectrum of 2-propen-1-ol is shown here. Indicate the protons in the molecule that give rise to each of the signals in the spectrum.
How could the signals in the 6.5-8.1-ppm region of their 1H NMR spectra distinguish among the following compounds?
A signal has been reported to occur at 600 Hz downfield from TMS in an NMR spectrometer with a 300-MHz operating frequency. a. What is the chemical shift of the signal? b. What would its chemical
The 1H NMR spectra of two compounds with molecular formula C11H16 are shown here. Identify the compounds.a.b.
Draw a splitting diagram for the Hb proton if Jbc = 10 and Jba = 5.
Sketch the following spectra that would be obtained for 2-chloroethanol: a. The 1H NMR spectrum for a dry sample of the alcohol b. The 1H NMR spectrum for a sample of the alcohol that contains a
How could 1H NMR be used to prove that the addition of HBr to propene follows the rule that says that the electrophile adds to the sp2 carbon bonded to the greater number of hydrogens.
Identify each of the following compounds from its molecular formula and its 1H NMR spectrum.a. C8H8b. C6H12O c. C9H18O QUESTION CONTINUE TO NEXT PAGE d. C4H8O
Dr. N. M. Arr was called in to help analyze the 1H NMR spectrum of a mixture of compounds known to contain only C, H, and Br. The mixture showed two singlets-one at 1.8 ppm and the other at 2.7
Calculate the amount of energy (in calories) required to flip an 1H nucleus in an NMR spectrometer that operates at 60 MHz.
The following 1H NMR spectra are for four compounds with molecular formula C6H12O2, Identify the compounds.a.b. c. QUESTION CONTINUE TO NEXT PAGE d.
When compound A (C5H12O) is treated with HBr, it forms compound B (C5H11Br). The 1H NMR spectrum of compound A has one singlet (1), two doublets (3, 6), and two multiplets (both 1). (The relative
Determine the structure of each of the following compounds based on its molecular formula and its IR and 1H NMR spectra.a. C6H12Ob. C6H14O QUESTION CONTINUE TO NEXT PAGE c. C10H13NO3 d. C11H14O2
a. If two signals differ by 1.5 ppm in a 300-MHz spectrometer, by how much do they differ in a 100-MHz spectrometer? b. If two signals differ by 90 hertz in a 300-MHz spectrometer, by how much do
Identify the compound with molecular formula C3H5Cl3 that gives the following 13C NMR spectrum.
Determine the structure of each of the following compounds based on its mass, IR, and 1H NMR spectra.a.b.
Identify the compound with molecular formula C6H10O that is responsible for the following DEPT 13C NMR spectrum.
Identify the compound with molecular formula C6H14 that is responsible for the following 1H NMR spectrum.
a. Which set of protons in each of the following compounds is the least shielded?1. CH3CH2CH2Cl2.3. b. Which set of protons in each compound is the most shielded?
a. What is the value of n in Hückel's rule when a compound has nine pairs of π electrons? b. Is such a compound aromatic?
a. Predict the relative pKa values of cyclopropene and cyclopropane. b. Which is more soluble in water, 3-bromocyclopropene or bromocyclopropane?
Which of the compounds in Problem 2 are antiaromatic?Problem 2a.b. c. Cycloheptatrienyl cation d. e. f. g. Cyclononatetraenyl anion h. CH2=CHCH=CHCH=CH2
How many bonding, nonbonding, and antibonding π molecular orbitals does cyclobutadiene have? In which molecular orbitals are the π electrons?
Can a radical be aromatic?
Following the instructions for drawing the Ï€ molecular orbital energy levels of the compounds shown in Figure 15.2, draw the Ï€ molecular orbital energy levels for the
Draw the structure of each of the following compounds: a. 2-phenylhexane b. Benzyl alcohol c. 3-benzylpentane d. Bromomethylbenzene
If electrophilic addition to benzene is an endergonic reaction overall, how can electrophilic addition to an alkene be an exergonic reaction overall?
Which compound will undergo an electrophilic aromatic substitution reaction more rapidly, benzene or hexadeuteriobenzene?
Why does hydration inactivate FeBr3?
The reaction coordinate diagram in Figure 15.5 shows that the rate-determining step for sulfonation is the slower of the two steps, whereas the rate-determining step for desulfonation is the faster
Which of the following compounds are aromatic?a.b. c. Cycloheptatrienyl cation d. e. f. g. Cyclononatetraenyl anion h. CH2=CHCH=CHCH=CH2
Show the mechanism for the generation of the acylium ion if an acid anhydride is used instead of an acyl chloride in a Friedel-Crafts acylation reaction.
Propose a mechanism for the following reaction:
Show the mechanism for alkylation of benzene by an alkene.
What would be the major product of a Friedel-Crafts alkylation reaction using the following alkyl halides? a. CH3CH2CI b. CH3CH2CH2Cl c. CH3CH2CH(CI)CH3 d. (CH3)3CCH2Cl e. (CH3)2CHCH2Cl f.
Describe how the following compounds could be prepared from benzene:a.b.
Which of the following compounds are aromatic? Are any antiaromatic?
Give the product of the reaction of excess benzene with each of the following reagents: a. Isobutyl chloride + AlCl3 b. Propene + HF c. Neopentyl chloride + AlCl3 d. Dichloromethane + AlCl3
Which ion in each of the following pairs is more stable?(a)(b) (c) (d)
Which can lose a proton more readily, a methyl group bonded to cyclohexane or a methyl group bonded to benzene?
How could you prepare the following compounds with benzene as one of the starting materials?(a)(b)
a. How many monobromonaphthalenes are there? b. How many monobromophenanthrenes are there?
Benzene underwent a Friedel-Crafts acylation reaction followed by a Clemmensen reduction. The product gave the following 1H NMR spectrum. What acyl chloride was used in the Friedel-Crafts acylation
Give the products of the following reactions:(a)(b) (c) (d)
Which compound in each of the following pairs is a stronger base? Why?a.b.
a. In what direction is the dipole moment in fulvene? Explain.b. In what direction is the dipole moment in calicene? Explain.
Purine is a heterocyclic compound with four nitrogen atoms.a. Which nitrogen is most apt to be protonated?b. Which nitrogen is least apt to be protonated?
Give the product of each of the following reactions:(a)(b)
Propose a mechanism for each of the following reactions:(a)(b)
Show two ways that the following compound could be synthesized:
The [10]- and [12]-annulenes have been synthesized, and neither has been found to be aromatic. Explain.
In what orbitals are the electrons represented as lone pairs when drawing the structures of quinoline, indole, imidazole, purine, and pyrimidine?
Answer the following questions by examining the electrostatic potential maps on p. 598: a. Why is the bottom part of the electrostatic potential map of pyrrole blue? b. Why is the bottom part of the
Predict the relative pKa values of cyclopentadiene and cycloheptatriene.
a. Draw arrows to show the movement of electrons in going from one resonance contributor to the next in 1. The cyclopentadienyl anion 2. Pyrrole b. How many ring atoms share the negative charge in 1.
Draw the resonance contributors of the cyclooctatrienyl dianion. a. Which of the resonance contributors is the least stable? b. Which of the resonance contributors makes the smallest contribution to
Name the following compounds:a.b. c. d.
a. Draw the resonance contributors for nitrobenzene. b. Draw the resonance contributors for chlorobenzene.
What product(s) would result from nitration of each of the following compounds? a. Propylbenzene b. Bromobenzene c. Benzaldehyde d. Benzenesulfonic acid e. Cyclohexylbenzene f. Benzonitrile
Are the following substituents ortho-para directors or meta directors? a. CH2=CHC≡N b. NO2 c. CH2OH d. COOH e. CF3 f. N=O
Which of the compounds in each of the following pairs is more acidic?
p-Nitrophenol has a pKa of 7.14, whereas the pKa of m-nitrophenol is 8.39. Explain

Showing 14200 - 14300 of 15575

First
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
Last

Services

Sitemap
Fun
Definitions
Become Tutor
Study Help Categories
Recent Questions
Expert Questions

Company Info

Security
Copyrights
Privacy Policy
Terms & Conditions
SolutionInn Fee
Scholarship

Get In Touch

About Us
Contact Us
Career
Jobs
FAQ
Campus Ambassador

Secure Payment

Download Our App

© 2024 SolutionInn. All Rights Reserved