0
Answering "http://wiki.answers.com/Q/How_do_you_calculated_the_percentage_of_an_isomer_using_proton_nmr"
Wiki User
∙ 14y ago
Add your answer:
Earn +20 pts
In the H NMR spectrum why does 1 2-dichloroethane show up as a singlet and not a triplet?
The molecule is symmetric so all protons are equivilent. Equivilent protons cannot couple with each other, so the spectrum is a singlet.
How molecular weight determined by nmr spectroscopy?
NMR isn't really used to determine molecular weight in general. It can be done for certain oligomers by, for instance, determining the ratio of end-group protons to protons that only occur in the "middle" of the chain.
What is meant by enantiotopic protons?
Enantiotopic Protons appear to be equivalent when replaced by a Deuterium and give one signal on NMR. However, they can be made nonequivalent when in a chiral environment (aka a "chiral resolving reagent").
Consider the silicon-29 isotope. How many protons neutrons and electrons will it have?
The silicon-29 isotope is used extensively in Nuclear Magnetic Resonance or NMR spectroscopy. It has 14 electrons, 14 protons and 15 neutrons.
Can you use NMR in characterisation of nanomaterials?
It depends of course on the specific material, but it being nano-sized makes no difference at all to the NMR spectrum. Nuclear Magnetic Resonance works on the principles of excitation and emission of the nucleus of the atoms. Only certain nuclei are capable of being monitored using NMR spectroscopy. What is required is a nucleus with an odd number of particles in it (such as carbon-13, hydrogen-1, fluorine-19, etc) which have odd spin. However such nuclei are common to most materials and therefore should allow the use of NMR for characterisation of nanoparticles. You can learn more about the types of nuclei and physical properties of nuclei at NMRCentral.com
In the H NMR spectrum why does 1 2-dichloroethane show up as a singlet and not a triplet?
The molecule is symmetric so all protons are equivilent. Equivilent protons cannot couple with each other, so the spectrum is a singlet.
What are the Factors which cause defects in NMR spectrum?
The main factor is the presence of water. If the sample is NOT fully dried of water it will cause a big 'spike' in the spectrum .
What is the NMR spectrum of acetylacetone?
what is the litreturevalue for enthalpy of enolization
Where does water show up in a proton NMR spectrum?
about 1.6 ppm, but you don't always see it
How molecular weight determined by nmr spectroscopy?
NMR isn't really used to determine molecular weight in general. It can be done for certain oligomers by, for instance, determining the ratio of end-group protons to protons that only occur in the "middle" of the chain.
Are protons magnets?
If you are studying NMR spectroscopy or MRI you can essentially view protons as little magnets that will line up along an external field.
What are the main differences in proton coupling and proton decoupling in c13 nmr?
Protons are not coupling. Only electrons can coupled.
The 1h and 31p nmr spectra of trimethyl phosphate are given below rationalise the appearance of both spectra?
the 1H nmr is a doublet and the splitting must arise from the 3 bond coupling between protons and phophorus
What is meant by enantiotopic protons?
Enantiotopic Protons appear to be equivalent when replaced by a Deuterium and give one signal on NMR. However, they can be made nonequivalent when in a chiral environment (aka a "chiral resolving reagent").
Consider the silicon-29 isotope. How many protons neutrons and electrons will it have?
The silicon-29 isotope is used extensively in Nuclear Magnetic Resonance or NMR spectroscopy. It has 14 electrons, 14 protons and 15 neutrons.
Why does an NH2 signal not show on a proton NMR?
Depending on the solvent used to dissolve the sample NH2 may or may not show up on h NMR. If it is dissolved in D2O (heavy water) deturium will exchange with the protons attached to heteoatoms and the signal will "dissapear"
What chemical tests would distinguish acetaminophen from ibuprofen?
melting point will definitely distinguish them since the melting point of acetaminophen is about 169 - 172 and ibuprofen is 75-78. You can also do an NMR spectroscopy and count the number of protons that you see.
