What are the main differences between an H-NMR spectra and a C-NMR spectra?  (1. The resonating nucleus. 2. Its natural abundance. 3. Use of decoupling techniques. - GS).

Can you talk about the Coupling Constant again and its significance? I’m not understanding it. The coupling constant shows by how much the resonance frequency of a nucleus is affected by the spin state of another nucleus. - GS).

How do you know which C=C bond in two different molecules will produce a stronger signal? Would you go over this in class? (It depends on the dipole moment change. - GS).

Can you explain homotrophic and enantiotrophic molecules in class? (Here is a good resource: http://www.masterorganicchemistry.com/2012/04/17/homotopic-enantiotopic-diastereotopic/  - GS).

How do you know if a signal is upfield or downfield? (Chemical shift increases from upfield to downfield. - GS).

How many different kinds of protons are in 1-chlorohexane? I found the answer to be 6 but I can only find 5 different types of protons. (Each of 6 carbons is bonded to a different type of protons, so the answer is 6. - GS).

^Can you explain how the protons connected to the 3 and 4 carbons of 1-chlorohexane are different? (Substitution of a proton of the first type with chlorine would give 1,3-dichlorohexane, while the substitution of the second one - 1,4-dichlorohexane. Substitution of chemically equivalent protons leads to the same compound. - GS).

How do you know whether something is in the ortho- or para- position’s affecting its pKa? (If that something stabilizes either conjugate acid or base by being involved into their resonance structures, - GS).

How do we tell the difference between an alkyne and an alcohol on an IR spectrum?  (Stretch of the triple bond. - GS).

On the Wiley homework there is a section about whether or not to expect an IR signal above or below 3000 cm^-1. For a few of the alkenes and alkynes it says that we should not expect a signal above 3000, but today in class we were told to expect C-H stretching above 3000 cm^-1. Can you clarify that? (This stretching is characteristic for H connected to an sp2- or sp-hybridized carbon, which is a part of a C=C bond or carbon-carbon triple bond. Therefore, this vibration will be observed for alkenes and alkynes with at least one H at a multiple bond, and will not observed for the rest of them. - GS).

If a molecule has a temporary dipole moment, is it infrared-inactive or infrared-active? (A molecule is infrared-inactive if the vibration does not change the dipole moment. All molecules undergo polarization and have very short-lived dipole moments. I have not heard that it affects their IR-behavior. But never say never, some ultrafast instrumentation might detect those fluctuations if they occur slower than IR-induced vibrations. - GS).

Is it possible to have a transmittance other than 0% and 100%? (Yes. It can be anywhere in between depending on how well the compound absorbs radiation, which in turn depends on the compound’s structure. - GS).