What is the difference between an enol and enolate? (Enol is one of the two conjugate acids of enolate. - GS).

Would Butanal and Methanol create a hemiacetal? (Yes, if they react at the 1:1 molar ratio. - GS).

Is methylation a real thing? We learned about nitration, but I don’t think we learned about methylation. (Yes. Methylation is an instance of alkylation, which we learned under nucleophilic substitution and aromatic electrophilic substitution.. It is very real. By methylation of nitrogens, a living body maps its genes to turn them on and off. - GS).

Which reactions can be complicated by carbocation rearrangements? (Any reaction proceeding through an carbocation intermediate. - GS).

Just to be sure, can we go over why cumulated is more stable than isolated? (Cumulated dienes are less stable than isolated, because they have fewer sigma-pi conjugations. - GS).

I’m still a little confused on why benzene will not react with bromine without a catalyst but cyclohexene will react readily without one? (This is an excellent demonstration of lower activity of aromatic compounds due to their stability. - GS).

Is the a difference in the mechanism of bromination and nitration? (Yes, only on the step of the electrophile preparation, which also leads to a different by-product. - GS).

What is an Allylic Carbon/Carbocation? (It is a carbon bonded to a C=C bond and everything (positive charge, atoms) attached to that carbon. If that C=C bond is a part of an aromatic ring, the term switches to “benzylic”. - GS).

Can you please review how the strength of a nucleophile/base is affected by the solvent? (In a protic solvent, nucleophilicity increases as the size of the nucleophilic atom increases. In aprotic solvents and in vacuum, nucleophilicity follows the trend of basicity. - GS).

If HCl is involved in an SN1 reaction, is free radical propagation is needed? (No. It is a 2 step non-chain reaction: http://ochem.orgfree.com/sn1.html  - GS).

When talking about acidity and basicity of alcohols, does the equilibrium shift towards the stronger acid? (No. It is shifted from a stronger acid to a weaker acid. - GS).

How do you know when to use anti-markovnikov’s rule? (Markovnikov’s rule is used for addition of non-symmetrical reagents to non-symmetrical multiple bonds. Examples of anti-Markovnikov addition: hydroboration followed by oxidation, free radical hydrobromination. A specific reaction mechanism will tell you whether or not the reaction proceeds by the rule.  - GS).

How do you figure out which carbon is the alpha carbon? (The first carbon attached to a functional group. - GS).

Is total energy always higher than potential energy? (No. It can also be equal, which means that the system does not move along that specific reaction coordinate. - GS).

Would you be able to explain NMR coupling strength between axial and equatorial hydrogens once more? How do you know which hydrogens will couple? (Axial H with an axial H at the adjacent carbon will couple the strongest, because the dihedral angle is 180o. Axial and equatorial hydrogens or equatorial and equatorial hydrogens also couple, but much weaker, because of the less favorable dihedral angle. - GS).   Thanks.

Would you be able to explain what a meso-form is? Is it just an achiral molecule? (Almost. It is an achiral molecule with chiral centers - GS). Thanks.

Does electronegative atoms cause shielding or deshielding of the atoms near it? (Deshielding, because shielding is caused by electrons. - GS). If there is deshielding then it is upfield and there is less of a chemical shift and if there’s shielding it’s more downfield and has more of a chemical shift correct? Am I backwards on this or do I have it correct? Thanks. (It is backwards, because shielding requires more field to overcome the shielding, so it is upfield. - GS).

If something is a triplet there are two coupling partners correct? (Yes, but the partners must be equivalent. - GS).

How do you assign octane ratings? (It is the percentage of isooctane in its mixture with n-heptane that has same resistance to detonation as the tested fuel. - GS).  

In class you said that eclipsed doesn’t always have higher energy and gave one example on when that wasn’t true. When there are hydroxide ions and hydrogen ions next to each other is when it isn’t true? (No. Those ions do not have valency to be attached to the carbon backbone, but other ions will work. - GS).

What exactly is coupling? I am confused with the H atoms and their spin. (It is dependence of the resonance frequency of a nucleus on the spin state of other nuclei (=its coupling partners) - GS).

What is the difference between electric and magnetic waves? Does one have higher wave frequencies than the other? (A change of the electric field causes a change of the magnetic field, and vice versa, so both components have same frequency. - GS).

I understand the vibration between certain bonds but if one has electric does it vibrate at high frequencies or not? I’m having a hard time grasping the broad idea of it.  (The IR absorption takes place only if it causes a change in the dipole moment of the molecule. - GS).