Chem

Question 1

SN1 Rxns

Answer 1

Question 2

SN2 Rxns

Answer 2

Question 3

Tautomerization

Answer 3

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.

Question 4

Aldol Formation and Condensation Reaction Mechanism

Answer 4

Question 5

Strecker Synthesis

Answer 5

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.

Question 6

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.

Answer 6

Question 7

Paramagnetic vs. Diamagnetic

Answer 7

Question 8

UV absorbance _______ as conjugation _______.

Answer 8

UV absorbance increases as conjugation increases.

Conjugated double bonds in a molecule, means that the single and double bonds alternate.

Question 9

Lewis Acids and Bases

Answer 9

Question 10

Bronsted Lowry Acids and Bases

Answer 10

Question 11

Reaction Between SOCl₂ and a Carboxylic Acid Derivative

Answer 11

Question 12

Graham’s Law of Effusion

Answer 12

Effusion= the rate at which gas escapes from a pinhole into a vacuum.

Question 13

pH=_______

Answer 13

pH = -log[H+]

Question 14

pH equals pKa when…

Answer 14

the pH is equal to the pKa there are equal amounts of protonated and deprotonated forms of the acid.

Question 15

Henderson-Hasselbalch Equation

Answer 15

Question 16

Ka = [?][?]/[?]

Answer 16

Question 17

Saponification

Answer 17

Saponification is the base hydrolysis of any ester into a carboxylic ion and an alcohol

Saponification can occur with any alkali base of hydroxide

Question 18

Beta + Decay

Beta - Decay

Electron Capture

Answer 18

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).

Question 19

Common NMR and IR Spectra Groups

Answer 19

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.

Question 20

Neutrons + Mass Number = ___________

Answer 20

Neutrons + Mass Number = Atomic Number

Question 21

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.

Answer 21

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.

Question 22

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.

Answer 22

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.

Question 23

__________, 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.

Answer 23

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

Question 24

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.

Answer 24

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.

Question 25

An _____ hydrogen is a hydrogen atom on an alpha carbon in an organic molecule; a hydrogen atom on a ____ carbon is a beta hydrogen

The _____ carbon in organic molecules refers to the first carbon atom that attaches to a ______, such as a carbonyl. The second carbon atom is called the ______ carbon.

Answer 25

An alpha (symbol: α) hydrogen is a hydrogen atom on an alpha carbon in an organic molecule; a hydrogen atom on a beta carbon is a beta hydrogen

The alpha carbon (Cα) in organic molecules refers to the first carbon atom that attaches to a functional group, such as a carbonyl. The second carbon atom is called the beta carbon (Cβ), and the system continues naming in alphabetical order with Greek letters.

Question 26

The acid-catalyzed ____________ begins with conversion of a ketone (or aldehyde) to an _____, which then attacks another aldehyde or ketone which has been activated by protonation of the carbonyl oxygen. This is referred to as the “aldol ______” reaction. The aldol ________ goes a step further: as the name suggests, water is removed from the aldol addition product, first by protonation of the alcohol, and then 1,4-elimination via an intermediate enol species to give a ______ enone.

Answer 26

The acid-catalyzed aldol condensation begins with conversion of a ketone (or aldehyde) to an enol, which then attacks another aldehyde or ketone which has been activated by protonation of the carbonyl oxygen. This is referred to as the “aldol addition” reaction. The aldol condensation goes a step further: as the name suggests, water is removed from the aldol addition product, first by protonation of the alcohol, and then 1,4-elimination via an intermediate enol species to give a conjugated enone.

Question 27

Define Conjugated Double Bonds

Answer 27

Conjugated double bonds in a molecule, mean that the single and double bonds alternate.

Question 28

_______ 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 _______relationship in organic chemistry is the

___-___ pair.

Answer 28

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.

Question 29

K_aK_b=?

Answer 29

K_aK_b​=K_w

where K_w is the dissociation constant of water and = 1x10¹⁴

Question 30

T(period)=1/?

Answer 30

T(period)=1/frequency

Question 31

The velocity of sound is slowest in _____ and fastest in _____.

Answer 31

The velocity of sound is slowest in air and fastest in solids.

Question 32

Mega = 1x10^?

Answer 32

Mega=1x10⁶