MCAT ORGANIC Chem Flashcards
1
Q
Does the term allotrope refer to elements, compounds, or both?
A
only Elements
2
Q
Are liquid water and water vapor 2 allotropes of H2O?
A
No.
Allotropes refer to different forms of an element IN THE SAME PHASE
3
Q
What kind of hybridization holds the carbon atoms together in graphite?
A
sp2
(p 428, Barrons)
4
Q
What does the term isomerism mean in chemistry?
A
Ability of atoms to arrange themselves in more than 1 way to give different compounds that have the same molecular formula (Nassau chem text by brady & senese)
atoms → different combinations → different compounds → same molecular formula
5
Q
What is the name/term for compounds with the same molecular formula, but with atoms connected in a different order, and thus have different properties?
A
constitutional isomers
6
Q
What’s another name for a constitutional isomer?
A
Structural isomer
7
Q
What’s the other variety of isomer, besides structural isomers?
A
Stereoisomers
8
Q
What is a stereoisomer?
A
molecules that have the same molecular formula, and have the same connections between the atoms, but have a DIFFERENT SPATIAL ORIENTATION
9
Q
What does it mean to have the prefix n- in a molecule’s name?
A
n- stands for normal. This means that the molecule’s spine/longest carbon chain is a straight chain
10
Q
What does trans- mean?
A
The groups attached to the double bonded carbons are on opposite sides.
11
Q
Which isomer gives a straighter-looking molecule? Cis- or trans-?
A
Trans- isomers
12
Q
True/False:
Cis- and trans- isomers have different chemical and physical properties
A
tru
13
Q
Are your hands superimposable?
A
no
14
Q
What is chirality?
A
“Handedness”. ‘
If one object is the mirror image of another object, AND if they are NOT superimposable, then these 2 objects are chiral.
15
Q
What makes something organic?
A
A compound is organic if its molecules contain carbon.
16
Q
Name 7 types/classes/groups of carbon-containing molecules that are NOT considered to be “organic.”
A
pure carbon and its allotropes,
CO2,
CO,
carbonates,
carbides,
cyanides,
thiocyanates, etc.
17
Q
generally, organic compounds are held together by _____ bonds
A
covalent
18
Q
CnH2n-2 is the general formula for which class of hydrocarbons?
A
alkynes
19
Q
What is the general algebraic formula for alkanes?
A
CnH2n+2
20
Q
What is the general formula for alkenes?
A
CnH2n
21
Q
what is the symbol for acidity constant?
A
Ka
22
Q
what’s another name/term for acidity constant?
A
Acid dissociation constant
23
Q
The (stronger/weaker) the acid, the (higher/lower) the Ka.
A
stronger
higher
24
Q
What is the relationship between Ka and pKa? (Hint: give the equation)
A
pKa =
- log Ka
25
A **(stronger/weaker)** acid has a **(higher/lower)** pKa.
Sronger;
lower
26
A strong acid yields a **(strong/weak)** conjugate base.
(p 46, McMurry)
weak
27
In electrostatic potential maps of molecules, what color is the **more** positively-charged region(s) of the molecule?
blue
28
\_\_\_\_\_\_\_ have a carbon bonded to a halogen
haloalkanes
29
What’s the other term for haloalkanes?
Alkyl halides
30
\_\_\_\_\_ have 2 carbon atoms bonded to the same oxygen
ethers
31
\_\_\_\_\_\_ have a C bonded to an N, and that same C is not double-bonded to an O
amines
32
\_\_\_\_\_ have a C bonded to an –SH group
thiols
33
\_\_\_\_\_\_ have 2 Carbon atoms bonded to the same sulfur
sulfides
34
T or F:
in functional groups, the bonds are polar
tru
35
in functional groups, the C has a partial ____ charge
positive
36
what is the *suffix* for an alcohol?
-ol
37
what is the suffix for an ether?
Ether. The word ether, by itself.
38
what is the suffix for an amine?
*-amine*
39
what is the suffix for a nitrile?
*-nitrile*
40
what is the suffix for a nitro?
there is none.
41
\_\_\_\_\_\_\_ a C that is both double-bonded to an O and also bonded to an N
amide
42
what is the suffix for an aldehyde?
*-al*
43
what is the suffix for a ketone?
*-one*
44
what’s another name for “straight-chain” alkanes? I.e., straight-chain alkanes are also known as _________ alkanes
“Normal” alkanes
45
when talking about alkyl groups, a primary carbon is bonded to \_\_\_\_\_\_ other carbon(s)
1
46
if an alcohol’s *–OH* functional group is attached to a carbon--that is itself attached to one other carbon--then that alcohol is called a **[primary/secondary/tertiary/quaternary]** alcohol
primary
47
generally, the symbol/letter **R** stands for
the *rest* of the molecule
48
the old-school, non-IUPAC name for alkanes was ______ ?
paraffins
49
alkanes are chemically **(reactive/inert)** to most laboratory reagents
inert
| (p 86)
50
with alkanes, boiling point and melting point show **(regular / irregular)** increases with increasing molecular weight
regular
| (p 87)
51
what causes the proportional, or direct or “regular”, increase in both the boiling point and melting point of alkanes?
**London dispersion forces** amongst the molecules, the intensity of which force *increases* with *increasing molecular size* of the alkanes
52
What effect does branching have on alkanes that have the same # of C atoms?
The more branching there is, the lower the boiling point
(mcmurry p 88)
53
Why is there an **inverse** relationship between the level of **branching** and the **boiling point** of alkanes?
Branched alkanes have **smaller surface area**, and thus **smaller London** dispersion forces
54
What’s the word used to describe hydrocarbons that are *NOT* aromatic?
aliphatic
55
T or F:
aliphatic compounds do not contain rings.
False.
## Footnote
“**Aliphatic**” refers to hydrocarbons that are ***not* aromatic**. But *not all ring-compounds are aromatic*.
56
in organic chem, what does the word **aryl** mean?
Refers to any **functional group** or substituent that has a simple **aromatic** ring
(wikipedia)
57
Given two isomers: if the isomers have **different connections between the atoms**, they are called “\_\_\_\_\_\_\_\_\_\_\_\_ isomers”
constitutional or structural isomers
58
What are **enantiomers**?
molecules that **are Mirror-images** of each other, but are **not superimposable**
59
What is meant by “conformation”?
the **3-dimensional shape** of a molecule *at any given instant*
60
What is a chirality center?
An **atom** that is bonded to **4 different** groups/substituents
61
What are **conformation isomers**? Describe/define it.
molecules that have the **same molecular formula**, and are just different arrangements of atoms that result from **rotation around a *single* bond**
62
What is torsional strain?
Strain in a molecule caused by **electron repulsion** between two segments (namely the **H’s** *on opposite ends* of the molecule) of the molecule that **eclipse each other *when*** *the molecule is viewed thru the length of its spine*
63
When talking about a molecule with a single bond, the lowest-energy, most stable conformation is the one in which all the H’s are **[**as far away from one another **/** as close to each other**]** as possible.
As far away from one another
64
The conformation of an ethane, at which all the hydrogens are as *far away* from each other *as possible* is called \_\_\_\_\_\_\_\_\_\_\_
[choices are below as a **hint**]
hint: it’s either *staggered* or *eclipsed*
staggered
65
If torsional strain of an ethane molecule can be measured, what is its amount?
12 kJ/mol
66
How much is 12 k**J**/mol in k**cal**/mol?
3kcal/mol
67
T or F:
## Footnote
conformational isomerism is a form of stereoisomerism in which the isomers can be interconverted by rotations about pi bonds
False.
## Footnote
**Conformational** isomers differ b/c of rotations around **single**, i.e. ***sigma***, bonds
68
The anti conformation is the [lowest/highest] energy conformation of a butane
lowest
69
What is steric strain?
the **repulsive** interaction that occurs when atoms are forced **closer together than their atomic radii allow**
(mcmurry 107)
70
why are a lot of cycloalkanes *not* shaped like “flat” rings where all the C’s are all on the *same plane*?
The “puckered,” or irregular shape, of the cycloalkane gives it zero *angle strain* and zero *torsional strain*
71
With which alicyclic compound is the **chair conformation** seen?
Cyclohex**a**ne
72
Due to the chair conformation, there are 2 kinds of positions for substituents on the ring: _____ positions and _______ positions.
**axial** positions, and
**equatorial** positions
73
The substituents of cyclohexane that are in the ______ position are perpendicular to the ring (i.e., parallel to the ring axis)
axial
74
What is a conformer?
Another name for a **conformational isomer**
75
What’s another name for two or more conformational isomers that differ only b/c of a rotation around just 1 single bond?
rotamer
76
At any given instant, about ____ % of ethane molecules have a *staggered* conformation and only about \_\_\_\_\_\_ % are close to the *eclipsed* conformation
(mcmurry 104)
99
1
77
Another name for a chiral center or chirality center is \_\_\_\_\_\_\_\_\_\_
(Hint: 2 words)
stereogenic center
| (berk review website)
78
Name the specific molecule/compound with which the term “**chair conformation**” is associated. I.e., *what’s the molecule* that comes to mind when you hear “chair conformation”?
cyclohexane
79
Besides the chair conformation, what other conformation(s) are possible with cyclohexanes? Name them.
Boat conformation
80
In a chair cyclohexane, what are the names of the two positions/orientations that the H atoms can have?
Axial and
equatorial
81
*How many* of the H atoms in a simple cyclohexane are in the **axial** position?
3
82
With monosubstituted cyclohexanes, a substituent is almost always more stable in an **[equatorial/axial]** position
equatorial
83
When you have a mixture of two isomers, which **equation** will allow you to calculate the *percentage* of each isomer in that mixture?
∆E = - RT ln K **← NOTE:**
this eqn can be used if the mixture is at equilibrium
84
∆E = - RT ln K
## Footnote
What does R stand for in the equation given above?
Gas constant
85
What is the actual *numerical value* of R (don’t forget the units)?
8.315 J/(K∙mol)
86
Why is there a difference between the potential energy of a cyclohexane with an **axial methyl** group and the potential energy of a cyclohexane with an **equatorial methyl** group?
The energy difference is caused by **steric** strain between the *methyl* group and the other *hydrogens*
(p 120)
87
Why are **1,3-diaxial interactions** so important? I.e., what are they responsible for?
This interactions results in the **steric** strain that is responsible for the energy difference between *axial* and *equatorial* conformers of a cyclohexane.
(mcmurry 120)
88
Which specific parts of a cyclohexane are involved in a 1,3-diaxial interaction?
The axial methyl group of a C1, and the H molecules of a C3 and C5
89
When talking about a ***trans***-disubstituted cyclohexane, the two substituents are: (see choices below):
(a) both axial
(b) both equatorial
(c) one axial and the other equatorial
(a) or (b)
90
Which is the more stable conformation: boat or chair?
Chair
91
What does the word “**polycyclic**” mean?
Refers to compounds that contain **two or more rings** that are **bonded** together
92
What’s the difference between “**polycyclic**” and “**heterocyclic**”?
**Hetero**cyclic refers to compounds having, as ring members, atoms of *at least two different elements *
(http://goldbook.iupac.org/H02798.html)
93
What’s the name of the *reaction* in which a single reactant undergoes a reorganization of bonds and atoms to yield an *isomeric* product?
Rearrangement rxn
94
What’s the name of a reaction in which 2 reactants add together to form a single new product with no atoms “left over”?
addition rxns
95
What’s the name of a rxn in which a single reactant *splits* into 2 products?
Elimination rxn
96
What’s the name of a rxn in which 2 reactants *exchange parts* to give 2 new products?
Substitution rxn
97
An overall description of a how a rxn occurs, is called a/an \_\_\_\_\_\_\_\_\_.
rxn mechanism
98
When a covalent bond breaks symmetrically so that 1 electron remains with each product fragment, the bond cleavage is called **[homolytic/heterolytic]**.
Homolytic
99
If a covalent bond forms when both bonding electrons are donated by just 1 of the reactants, this type of bond making is called **[homogenic/heterogenic]** bond making.
Heterogenic
100
Radical rxns involve **[symmetrical/asymmetrical]** bond breaking and bond making
symmetrical
101
The opposite of ‘radical rxn’ is a ‘\_\_\_\_\_ rxn’
polar
102
**[Larger/smaller]** atoms are more polarizable.
Larger
103
Why are larger atoms more polarizable?
b/c their electrons are *more loosely held* than smaller atoms
104
The electron-*poor* reactant is called an/a (Hint below)
Hint: \_\_\_\_phile
Electrophile
105
True/false:
## Footnote
an electrophile may be either neutral or negatively charged
False.
## Footnote
Correct answer is, that an electrophile can be
either neutral or *positively* charged.
106
Lewis bases are **[nucleophiles/electrophiles]**.
Lewis **bases** are electron **donors** and behave as **nucleo**philes.
107
another name for a carbon cation is \_\_\_\_\_\_\_.
carbocation
108
True/false:
Carbocations can accept electron pairs
tru
109
The word endergonic is associated with the **[****Δ**** H / ****Δ**** G / ****Δ**** S]** of a rxns.
Δ G
110
The fancy term for Δ G is ‘\_\_\_\_\_\_\_\_\_ change’
Gibbs free-energy change
111
The fancy term for Δ H is ‘\_\_\_\_\_\_ change’
enthalpy change
112
What is the symbol for ‘bond dissociation energy’?
D
113
Define **bond dissociation energy**
amount of energy required to break a given bond to produce **2 radical fragments** when the molecule is in the **gas** phase at **25 degrees** Celsius
114
**[Cis/trans]** alkenes are more stable
trans
115
Why are **trans** alkenes more stable?
b/c *cis* alkenes have **steric** strain between the 2 substituents that are on the same side of the double bond
116
True or False:
the more substituted the alkene, the more stable it is.
true
117
In Orgo, when you hear the word “**attack**” being used, which specific atom/molecule/particle is the "attacker"?
Electrons
118
What is **Markovnikov’s rule**?
(Hint: not the one referring to carbocations)
In the addition of a given molecule ‘H-X’ to an alkene, the **H** atom bonds to the double-bonded carbon that has FEWER **alkyl substituents** connected to it.
The **X** attaches to the double bonded carbon that has MORE alkyl substituents.
119
What’s Markovnikov’s rule when **restated to include cations**?
In the addition of H-X to an alkene, the **more substituted** carbocation is formed as the **intermediate** rather than the less highly substituted one.
120
True or false:
## Footnote
the **more** substituted a carbocation is, the **less** stable it is.
False.
## Footnote
**More** highly **substituted** carbocations are more **stable** than less highly substituted ones.
121
What’s the name of the stabilizing interaction between a vacant *p* orbital and a properly oriented neighboring C-H *sigma* orbital (mcmurry p. 191)?
Hyperconjugation
[*is this really* important for the MCAT??]
122
What is an alkyl group?
An alkane that is missing one hydrogen
123
What is the Hammond postulate?
Basically it states that we can get a picture of what given transition state looks like, by looking at the structure of the nearest stable species.
Thus **exer**gonic rxns have transition states that resemble **reactant**;
**ender**gonic rxns have transition states that resemble **product**.
124
When an *s* and a *p* orbital combine to form a hybrid orbital, what is the total # of orbital(s) formed?
2
125
What is the mathematical expression that tells u the number of hybrid orbitals on a given atom with a hybridization of ‘*sp*x’?
1 + x
126
**1 + x** is the eqn that tells u the number of hybrid orbitals on a given atom with a hybridization of ‘*sp*x’.
What are all the potential numerical values of **X** in the above expression?
1, 2, or 3
127
What expression tells you the percentage of the “*s* character” for any given orbital of *sp*x?
1 **/** (1+x)
128
What percentage of an *sp*2 orbital has the *p* character?
67%
[use the formula **x/1+x**]
129
If a given atom in a molecule has a *sum* of **2** attached **atoms** and *lone* electron **pairs**, what is its hybridization?
*sp*
130
If a given atom in a molecule has a **sum** of 4 attached **atoms** and lone electron **pairs**, what is its hybridization?
*sp*3
131
What molecular geometry does an *sp* hybridization have?
Linear
132
What is the bond angle for an *sp*2 hybridization?
120
133
What is the bond angle for an *sp*3 hybridization?
109.5 degrees
134
T or F:
a saturated molecule contains *pi* bonds
false
135
What expression shows how many H atoms are present in a saturated compound that has *n* carbon atoms?
2*n* + 2
136
A \_\_\_\_\_-bond is formed by the parallel, side-to-side alignment of 2 unhybridized *p* orbitals on adjacent atoms.
π
137
What is bond dissociation energy?
The energy required to break a bond **homo**lytically
138
When a bond is broken and both electrons go to just one of the resulting fragments, this kind of bond-breaking or bond-cleavage is called \_\_\_\_\_\_\_ (adjective)
heterolytic
139
Which type of bond cleavage results in the formation of two radicals?
Homolytic
140
When comparing the same type of bonds, the greater the *s* character in the bonding orbitals, the **[longer/shorter]** the bond
shorter
| (p 452, TPRH bio)
141
Which bond would you expect to be shorter: an *sp-s* bond, or an *sp*3-*s* bond?
*sp-s* bond is shorter
142
Another name for a chiral center or stereogenic center is \_\_\_\_\_\_\_
stereocenter
143
What exactly is a chiral center?
An atom that has **4 different** groups bonded to it.
144
In Orgo, a chiral center is usually which element?
carbon
145
What are enantiomers?
Isomers that are **mirror images** of each other **AND** are **chiral**.
146
What is the name for stereoisomers that are not mirror images?
(I.e., the overall name for the *entire category*, not just a specific subtype or variety)
diastereomer
147
T or F:
*cis*-*trans* isomers are a type of enantiomer
False.
## Footnote
Cis-trans isomers fall under the category of Diastereomers
148
Do enantiomeric pairs have differences in melting point?
no
149
Do enantiomeric pairs have differences in boiling point?
no
150
Do enantiomeric pairs have differences in dipole moment?
No (p 462, TPRH bio)
151
Do enantiomers have differences in their optical activity?
yes
152
What mathematical expression tells us how many stereoisomers a molecule can possibly have if it has *n* chiral centers?
2n
153
Can a molecule with *n* chiral centers have more than 2n stereoisomers?
no
154
Can a molecule with *n* chiral centers have less than 2n stereoisomers?
yes
155
What is a meso compound?
Molecule that has at least 1 chirality center, but has a **plane of symmetry** and thus is **a**chiral
156
What are epimers?
**Diastereo**mers that differ in their absolute configuration at ONLY ONE chiral center
157
For naming alkenes, the cis-trans naming convention only works with \_\_\_\_-substituted alkenes. (possible answer choices below)
Choices: mono-, di-, tri-, tetra-
di
158
What’s the name of the naming system developed for alkenes that are trisubstituted and tetrasubstituted?
E,Z system
159
What is ‘**absolute configuration**’?
the exact 3-dimensional structure of a chiral molecule
160
What set of rules are used to determine a molecule’s absolute configuration?
the Cahn-Ingold-Prelog rules
161
Epimers that form as a result of ring closure are known as \_\_\_\_\_\_
anomers
162
What specific type of organic molecules will you see the term ‘anomer’ associated with?
Sugars (saccharides)
163
Glucose in its ring form is called \_\_\_
glucopyranose
164
What are geometric isomers?
Diastereomers that differ in the *orientation* of substituents around a *ring* or a *double bond*
165
Name 2 types of geometric isomers commonly encountered in Orgo.
Cis-trans isomers; and
E,Z isomers
166
Describe the relationship between a molecule’s optical activity and its absolute configuration.
There is **no correlation** between a molecule being dextrorotary/levorotary and it being R or S
167
Hydrocarbons are generally nonpolar, yet can attract/repel each other to some extent.
Which force allows for these interactions among otherwise nonpolar molecules?
van der Waals forces, *specifically* **London** dispersion forces.
168
Does branching have any effect on boiling point and melting point for hydrocarbons?
yes
169
Branching **[raises/lowers]** the melting point of a hydrocarbon.
lowers
170
Branching **[raises/lowers]** the boiling point of a hydrocarbon.
Lowers
171
Increasing molecular weight **[increases/decreases]** MP of hydrocarbons.
increases
172
Increasing molecular weight **[increases/decreases]** BP of hydrocarbons.
increases
173
In organic chem, which structures/atoms/functional groups can function as hydrogen acceptors for a hydrogen-bond?
A lone pair of electrons on a **nitrogen**, an **oxygen**, or **fluorine** can accept an H an make a hydrogen bond
174
Can the oxygen of a hydroxyl group function as an H-acceptor for a hydrogen bond?
YES
175
In organic chem, which structures/atoms/functional groups can function as hydrogen donors for a hydrogen-bond?
An H that **is attached to an N, an O, or an F**, can fncn as a hydrogeon bond *donor*
176
Given several molecules that contain oxygen, how do you rank them in order of *increasing* boiling point?
For each molecule, count the number of **oxygens**. Each oxygen equals one hydrogen-bond **acceptor**.
Count the number of **Hydrogens** *that are bonded to an N, O, or F*. These are hydrogen **donors**.
Order the molecules according to the **sum of** hydrogen **acceptors** and hydrogen **donors**.
177
What does the *solubility* of a hydrocarbon depend on?
The polarity of the solute, and the polarity of the solvent.
178
The dipole moment of a hydrocarbon is:
(a) very small to zero
(b) moderate to very large
very small to zero
179
As a general rule, hydrocarbons containing **[#]** or fewer carbons have good solubility in water.
[What is the number?]
6
180
Nucleophilicity **[increases/decreases]** going down the periodic table within a particular group
increases
181
Chloride anion, hydroxyl group, ammonia, cyanide PAI, unattached hydroxyl PAI, ethane are examples of **[nucleophiles/electrophiles]**
nucleophiles
182
Nucleophilicity **[increases/decreases]** as electronegativity decreases.
Increases
183
What are **electrophiles**?
[TPRH has an excellent definition on p 478]
species that have a positive or partial positive charge and, frequently, have in incomplete octet
184
Electrophilicity **[increases/decreases]** as negative charge increases
decreases
185
Carbonium ions are also called \_\_\_\_\_\_\_\_\_\_.
carbocations
186
Most organic rxns proceed thru one of these 3 types of intermediate species:
carbocations;
alkyl radicals; or
carbanions
187
on the MCAT, __________ will always be *sp*2 hybridized with an empty *p* orbital
carbocations
188
on the MCAT, alkyl radicals will be ___ hybridized with the unpaired electrons in an unhybridized ___ orbital.
* sp*2;
* p*
189
What are alkyl radicals?
Rxn intermediates that contain 1 unpaired electron
190
Regarding the 3 rxn intermediates: the less substituted a/an _________ is, the more stable it is.
carbanion
191
What is a relationship between the *reactivity* of an alkyl radical and its *degree of substitution*?
The **more** substituted the alkyl radical is, the **less** reactive it is.
192
What is the relationship between the *reactivity* of a carbocation and its *degree* of substitution?
The **more** substituted the carbocation is, the **less** reactive it is.
193
What is the relationship between a carbanion’s reactivity and its degree of substitution?
The ***more*** substituted a carbanion is, the **more** reactive it is.
194
What is the relationship between an alkyl radical’s **energy** and its degree of substitution?
The **higher** the alkyl radical’s energy, the **less** substituted it is.
195
What is the relationship between a carbanion’s level of substitution and its energy?
The more substituted the carbanion is, the higher its energy
196
What are **4** common examples of **electrophiles** according to TPRH p. 478?
Hydrogen ion,
carbon that is double-bonded to oxygen,
carbocation, and
borane
197
what is the molecular formula of borane?
BH3
198
Generally, the major product of a rxn is derived from the **[most/least]** stable intermediate.
(p 479, TPRH)
MOST
199
What are the two major ways by which organic intermediates are stabilized?
Inductive effects, and
resonance effects
200
Functional groups or substituents that surround a reaction intermediate will pull electrons towards them (i.e., away from the intermediate) if they are **[more/less]** electronegative than the intermediate.
If the *substituent* is MORE electronegative than the *intermediate*
201
on the MCAT, alkyl substituents always **[donate/withdraw]** electrons to/from the rxn intermediate
donate electrons to the intermediate
[p 479; TPRH]
202
Name the electron-deficient intermediate(s) found in orgo.
Carbocations, and
radicals
203
Define the ‘inductive effect’
the stabilization of reaction intermediates by the sharing of electrons thru *sigma* bonds
204
What does it mean to say that an electron is **localized**?
‘localized’ means it is **confined to one orbital**, which can be either
a bonding orbital between 2 atoms, or
a lone-pair orbital
205
Resonance structures usually involve electrons that are adjacent to (i.e., 1 atom away from) a/an:
pi bond or an unhybridized *p* orbital
| (p 485, TPRH)
206
What tells you that a resonance structure can NOT be drawn for a particular atom?
If the atom **is *sp*3 hybridized**, it cannot appear in resonance forms
207
A Bronsted-Lowry acid **[donates/accepts]** a \_\_\_\_\_\_\_\_
donates a proton
208
The hybridization of a triple bond (e.g., alkYnes) is **[sp / sp2 / sp3]**.
*sp*
209
The most stable type of bond between atoms is **[sigma / pi]**.
sigma
210
What does **conjugation** mean, in Orgo?
Alternating single and double bonds.
211
In organic chemistry, what does the term **geminal** mean?
refers to the relationship between two **atoms** or functional **groups** that are **attached to the same atom**
212
The **[smaller / larger]** the molecular weight, the **[higher / lower]** the density.
The ↓↓ the molecular WEIGHT, the ↓↓ the density.
213
Combustion reactions are **[endothermic / exothermic / nonspontaneous]**.
**EXO**thermic
214
(1) The **most** stable cycloalkane has **_[#]_** carbons.
(2) The *second* most stable cycloalkane has **_[#]_** carbons.
**6**
5
215
In a radical reaction that has an Initiation, Propagation, and Termination steps, which of these steps feature **homolytic** bond cleavage?
Only the Initiation step has **homolytic** bond cleavage.
216
Order the **Halogen radicals** from MOST reactive to LEAST reactive.
F \> Cl \> Br \> I
217
Which of the following is/are required for the Hydrogenation of an alk**E**ne?
## Footnote
**[Metal catalyst / high temperature / both / neither]**
metal catalyst
218
T/F:
## Footnote
When an alkEne reacts with an hydrogen halide (H-X), but in the presence of peroxide, the resulting alkyl halide product will be *anti*-Markovnikov.
***partially*** True.
## Footnote
The anti-Markovnikov effect, created by the presence of peroxide, only works with H***Br* **reactants, and NOT with reactions that have HCl or HI as reactants.
219
When an **alkEne** reacts with an hydrogen bromide (**HBr**), but **in the presence of peroxide**, the resulting alkyl halide product will be anti-\_\_\_\_\_\_.
Markovnikov
220
When an alk**E**ne reacts with a hydrogen bromide (**HBr**), but in the presence of a \_\_\_\_\_\_\_, the resulting alkyl halide will be ***anti***-Markovnikov.
peroxide
221
In an **oxymercuration-demercuration** reaction, the alcohol product that is formed is **[Markovnikov / anti-**Markovnikov**]**.
Markovnikov
222
Are **rearrangements** (i.e., switiching Hydrogens or Methyl groups around) possible in an **oxymercuration-demercuration **reaction?
No
223
In **hydroboration-oxidation** reactions, the alcohol product is formed from the **[syn / anti]** addition, of an -OH and an H, to an alkene.
syn
224
In the **hydrogenation** of alk**e**nes using a metal catalyst, the Hydrogens are added to the alkene in a **[syn / anti] **addition.
syn
225
EMR in the **infrared** (IR) range has a wavelength from ___ to ___ **_milli_**meters.
**2.5** to **20** mm
226
In IR spectroscopy, what is **wavenumber**?
the reciprocal (inverse) of the wavelength at which the organic molecule's covalent bonds will vibrate
227
In IR spectroscopy, wavenumbers are measured in this unit:
reciprocal centimeters (**cm-1**)
228
In a IR spectroscopy graph, what are the labels of the axes?
**Y**-axis: **Transmittance**
**X**-axis: **Wavenumber**
229
In IR spectroscopy, the **carbonyl**"stretch" is centered around *what wavenumber*?
**1700** cm-1
230
In IR spectroscopy, the "stretch" for the **alkene** double bond is centered around *what wavenumber*?
1650
231
In IR spectroscopy, the **triple bond**"stretch" is centered around *what wavenumber*?
**2600** - **2100**
232
In IR spectroscopy, describe the **-OH**"stretch":
very steep, and very broad
3600 - 3200
233
In IR spectroscopy, how do we tell apart the "stretch" of a ***aliphatic* C-H** bond, versus an ***aromatic*** C-H bond?
* **aliphatic** C-H bonds stretch at a **little *less* than 3000**;
* **aromatic** C-H bonds stretch at wavenumbers **slightly *greater* than** 3000
234
In IR spectroscopy, the "stretch" wavelength for any kind of **C-H** bond is around:
3300 - 2850
235
In IR spectroscopy, how do we distinguish the "stretch" of *different* types of **C-H** bonds?
* for *sp***3** carbons, the stretch is around **3000 to 2850**
* for *sp***2** carbons, the stretch is around **3150 to 3000**
* for ***sp*** carbons, the stretch is around **3300**
236
What does *shift* or *chemical shift* mean when talking about NMR spectroscopy?
the location of the sets of peaks in the NMR spectrum
237
For hydrogen NMR spectroscopy, along which numerical value(s) on the X-axis will you find **halogens**?
3 - 5
238
For proton NMR spectroscopy, along which numerical value(s) will you find **aromatics**?
7
239
For proton NMR spectroscopy, along which numerical value(s) will you find **carboxyl** groups?
10 - 12
240
For proton NMR spectroscopy, along which numerical value(s) will you find **aldehydes**?
9 - 11
241
For hydrogen NMR spectroscopy, along which numerical value(s) on the X-axis will you find **alkyne triple bonds**?
~ 2
242
For hydrogen NMR spectroscopy, along which numerical value(s) on the X-axis will you find **ketones**?
1 - 2
243
For hydrogen NMR spectroscopy, along which numerical value(s) on the X-axis will you find **benzyl **groups?
~ 3
244
Which of the following cycloalkanes has the ***lowest*** heat of combustion, per **—CH2—** (i.e., methylene) group?
* cyclopropane
* cyclobutane
* cyclohexane
* cycloheptane
cyclo**hex**ane
245
The **Iodoform Test** is used for:
to detect the presence of a **carbonyl group with a methyl group bonded to it**. E.g., methyl ketones, and acetaldehyde will give a *positive* Iodoform test.
246
How do you know you have a *positive* **Iodoform test**?
The formation of a **yellow precipitate **
247
Organic (i.e., carboxylic) Acid **+** Alcohol → **????**
→ **_ESTER_** **+** water
248
Alcohol + **\__????_\_** → Ester + H20
organic (i.e., carboxylic) Acid
249
A **saponification** rxn involves reacting a ____ with a \_\_\_\_.
* inorganic base (e.g., NaOH);
* ester
250
Ester **+** inorganic Base → **????**
→ **Soap** + alcohol
