Chem Flashcards
SN1 Rxns
SN2 Rxns
Tautomerization
Tautomers are two molecules with the same molecular formula but different connectivity - constitutional isomers, in other words - which can interconvert in a rapid equilibrium. The most common tautomeric relationship in organic chemistry is the keto-enol pair.
Aldol Formation and Condensation Reaction Mechanism
Strecker Synthesis
The Strecker amino acid synthesis, also known simply as the Strecker synthesis, is a method for the synthesis of amino acids by the reaction of an aldehyde with ammonium chloride in the presence of potassium cyanide.
Solubility Guidelines
All group I and ammonium salts are ______.
All nitrates, perchlorates, and acetates are _______.
All halides are ______ except halide salts formed with silver, lead, mercury, and copper.
All sulfates are _______ except sulfates formed with ______, ______, _______, _______, or _________.
All carbonates are _________ except salts of the alkali metals and ammonium.
Paramagnetic vs. Diamagnetic
UV absorbance _______ as conjugation _______.
UV absorbance increases as conjugation increases.
Conjugated double bonds in a molecule, means that the single and double bonds alternate.
Lewis Acids and Bases
Bronsted Lowry Acids and Bases
Reaction Between SOCl2 and a Carboxylic Acid Derivative
Graham’s Law of Effusion
Effusion= the rate at which gas escapes from a pinhole into a vacuum.
pH=_______
pH = -log[H+]
pH equals pKa when…
the pH is equal to the pKa there are equal amounts of protonated and deprotonated forms of the acid.
Henderson-Hasselbalch Equation
Ka = [?][?]/[?]
Saponification
Saponification is the base hydrolysis of any ester into a carboxylic ion and an alcohol
Saponification can occur with any alkali base of hydroxide
Beta + Decay
Beta - Decay
Electron Capture
Beta + decay: you emit a positron (+), in turn converting a proton to a neutron (think charge balance, you “lost” and emitted the positive charge of the proton, in turn forming a neutron). Mass number stays the same, Z decreases by 1.
Beta - decay: you emit an electron, in turn converting a neutron to a proton (again charge balance, you “lost” and emitted negative charge from a neutron, loss of negative creates a positive proton). Mass number stays the same, Z increases by 1.
- electron capture: think of the incoming electron as “fusing” with a proton and converting it to a neutron. Extending this model, + positron capture would convert a neutron to a proton (although in reality this isn’t a thing).
Common NMR and IR Spectra Groups
IR:
Broad peak at 3300 cm-1 > O-H
Carboxylic acids > 3000 cm-1
Sharp peak at 3300 cm-1 > N-H
Sharp peak at 1750 cm-1 > C=O
NMR:
Hydrogens on sp3 carbons > 0 to 3 ppm
Hydrogens on sp2 carbons > 4.6 to 6.0 ppm
Hydrogens on sp carbons > 2.0 to 3.0 ppm
Aldehyde Hydrogens > 9 to 10 ppm
Carboxylic acids Hydrogens > 10.5 to 12 ppm
Aromatics Hydrogens > 6.0 to 8.5 ppm
Anything around 3000 cm-1 involves a hydrogen atom, be it O-H, N-H, or C-H.
Anything around 2000 cm-1 and below does not involve hydrogen, be it C=O, C=C, C-C, or C-O.
With the same atoms, the higher the bond order, the faster it vibrates, and so the higher the wavenumber.
1700 cm-1 is for the carbonyl group. Remember this.
3300 cm-1 can be O-H, N-H, or alkyne C-H. OH is the broadest, N-H slightly sharper, alkyne C-H is very sharp.
Broad peaks are due to hydrogen bonding (OH and NH).
Below 1300 cm-1 is called the fingerprint region.
Patterns in the fingerprint region are unique for each compound just like a fingerprint is unique for each person.
Neutrons + Mass Number = ___________
Neutrons + Mass Number = Atomic Number
As you move across a period, _______ increases. WHY? - As you move across a period, the atomic radius decreases, that is, the atom is smaller. The outer electrons are closer to the nucleus and more __________ to the center.
As you move across a period, first ionization energy increases. WHY? - As you move across a period, the atomic radius decreases, that is, the atom is smaller. The outer electrons are closer to the nucleus and more strongly attracted to the center.
Electron affinity increases _____ for the groups and from ____ to _____ across periods of a periodic table because the electrons added to energy levels become ______ to the nucleus, thus a stronger attraction between the nucleus and its electrons.
Electron affinity increases upward for the groups and from left to right across periods of a periodic table because the electrons added to energy levels become closer to the nucleus, thus a stronger attraction between the nucleus and its electrons.
__________, sometimes called dismutation, is a redox reaction in which one compound of intermediate oxidation state converts to two compounds, one of ______ and one of ______ oxidation states.
Disproportionation, sometimes called dismutation, is a redox reaction in which one compound of intermediate oxidation state converts to two compounds, one of higher and one of lower oxidation states
It is typical for _____-phase chromatography on silica that the mobile phase is 100% organic; no water is used. The term ______-phase describes the chromatography mode that is just the opposite of normal phase, namely the use of a_____ mobile phase and a ______ or _______ stationary phase.
It is typical for normal-phase chromatography on silica that the mobile phase is 100% organic; no water is used. The term reversed-phase describes the chromatography mode that is just the opposite of normal phase, namely the use of a polar mobile phase and a non-polar [hydrophobic] stationary phase.
