Prelim 1 Flashcards
(150 cards)
1
Q
How many bonds does C need for an octet?
A
4 bonds
2
Q
What is a stable octet?
A
8 valence electrons
3
Q
What do Lewis structures consist of?
A
Lewis structures consist of:
- dots showing individual electrons
- “lone pairs”, which are 2 electrons next to each other
- 1-3 lines between 2 atoms (can be the same type of atom) indicating a bond
- the shorthand for the atom name (ex: C, N, H, O, etc.) written at the ends of each line indicating the atoms bonded to each other
4
Q
What do condensed structures look like?
A
Condensed structures are a shorthand for drawing Lewis structures that consist of the atoms of the Lewis structures written in an ordered, single line.
Ex: CH3CH2CH2CH2CH2CH3 or CH3(CH2)4CH3
*Pretend the 3 is a subscript
5
Q
What are the rules for creating condensed structures?
A
- Atoms of the longest chain* must be written
horizontally - Ligands (atoms that are bound to another atom) are
written to the atom’s right
Ex: NH3 (H3, the ligand, is written to the right of N) - Lone pairs of e- are not shown
- Collapsing atoms
- Subscripts are used to depict the # of atoms - Parentheses used to depict polyatomic ligands bonded
to another atom
Ex: HOCH2CH2CH(NH2)CH3 - Bonds to C are omitted
- If necessary, use explicit bonds to clarify
attachment
*What counts as the “longest chain” depends on the molecule
6
Q
What do Lewis structures look like?
A
Lewis structures:
H H H H H
| | | | |
H --- C ---- C --- C ---- C ---- C --- H
| | | | |
H H H H H
7
Q
What do line-bond/skeletal structures look like?
A
/\/\/
8
Q
What are the rules for creating line-bond/skeletal structures?
A
- Every “corner” is a C (unless labeled otherwise)
- Every line end is a C (unless labeled otherwise)
- Hs on Cs are invisible
- Exception: If C is explicitly written, then its bonded
Hs must be written - Hs on heteroatoms drawn, not necessarily w/ a bond
- It CAN be drawn w/ a bond if you want to draw it - Lone pairs (non-bonding e-) on heteroatoms are
optional
- Exception: If the lone pair(s) are being used in a
mechanism/indicated you must draw them - Complete octets on nearly everything
- Exception: H (2 ve-), sometimes B*, etc.
9
Q
What’s special about Halogens?
A
- Halogens have 8 ve-
- Halogens do not make bonds because they are stable
10
Q
How to find the number of ve- in an atom?
A
Consult the periodic table:
- At the top of each column in some periodic tables it will have a number 1-8, which informs you how many valence electrons the elements in that column has
11
Q
How many lone pairs are assumed in O?
A
2 lone pairs (4 electrons)
12
Q
How many lone pairs are assumed in N?
A
1 lone pair (2 electrons)
13
Q
How many lone pairs are assumed in Br?
A
3 lone pairs ( 6 electrons)
14
Q
What is the rule for nonbonding e- on C?
A
Non-bonding e- on C must be explicitly drawn.
15
Q
What is the rule for nonzero formal charges?
A
Nonzero formal changes MUST be shown.
16
Q
What is the formal charge of a C w/ one bond?
A
The formal charge does not exist.
17
Q
What is the formal charge of a C w/ 3 bonds?
A
- Positive
- Negative
- No formal charge
18
Q
What is the formal charge of an N w/ 1 bond?
A
- The formal charge does not exist.
19
Q
What is the formal charge of an N w/ 2 bonds?
A
- Positive
20
Q
What is the formal charge of an N w/ 3 bonds?
A
- No formal charge
21
Q
What is the formal charge of an N w/ 4 bonds?
A
- Positive
22
Q
What is the formal charge of an O w/ 1 bond?
A
- Negative
23
Q
What is the formal charge of an O w/ 2 bonds?
A
- No formal charge
24
Q
What is the formal charge of an O w/ 3 bonds?
A
- Positive
25
What is the formal charge of an O w/ 4 bonds?
- The formal charge does not exist
26
What is the formal charge of a halogen w/ 1 bond?
- No formal charge
27
What is the formal charge of a halogen w/ 2 bonds?
- Positive
28
What is the formal charge of a halogen w/ 3 bonds?
- The formal charge does not exist
29
What is the formal charge of a halogen w/ 4 bonds?
- The formal charge does not exist
30
How many ve- does C have?
4 ve-
31
How many ve- does H have?
1 ve-
32
How many ve- does O have?
6 ve-
33
How many ve- does N have?
5 ve-
34
How many ve- does P have?
5 ve-
35
How many ve- does S have?
6 ve-
36
How many bonds does H need for an octet?
1 bond
37
How many bonds does O need for an octet?
2 bonds
38
How many bonds does N need for an octet?
3 bonds
39
How many bonds does P need for an octet?
3 bonds
40
How many bonds does S need for an octet?
2 bonds
41
How to determine the number of ve- (in an entire molecule)
- Find the sum of all the different ve- contributions from every atom present in the molecule
Ex: Find the number of ve- in H2S
*Pretend 2 is a subscript
H: 1 ve- S: 6 ve- # ve- = 1 ve- + 1ve- + 6ve- = 8ve-
(2 Hs= 2 ve-)
42
Hydrocarbon w/ CC single bonds.
- Alkane
43
Hydrocarbon w/ CC double bonds
- Alkene
44
Hydrocarbon w/ CC triple bonds
- Alkyne
45
A functional group where in the hydrocarbon setup, a halogen(s) will take the place of hydrogen. (single bond)
-Halide
46
-ane
- Alkane
47
-ene
- Alkene
48
-yne
- Alkyne
49
C single bonded to one OH group
- Alcohol
50
-ol
- Alcohol
51
C single bonded to one SH group
- Thiol
52
-thiol
- Thiol
53
O single bonded to C on either side
- Ether
54
-sulfide
- Sulfide
55
S single bonded to C on either side
- Sulfide
56
-disulfide
- Disulfide
57
2 Ss single-bonded to each other and single-bonded to one C on either side
- Disulfide
58
-amine
- Amine
59
C single bonded to N
- Amine
60
C double bonded to N
- Imine
61
-nitrile
- Nitrile
62
C triple bonded to N
- Nitrile
63
C double bonded to O
- Carbonyls
64
-al
- Aldehyde
65
C double bonded to O and single bonded to 1 H
- Aldehyde
66
-one
- Ketone
67
C double bonded to O and single bonded to 2 Cs
- Ketone
68
-oic acid
- Carboxylic acid
69
C double bonded to O and single bonded to an OH group
- Carboxylic acid
70
(-CN)
- Nitrile
71
(-COH)
- Aldehyde
72
(-COOH)
- Carboxylic Acid
73
-oate
- Ester
74
O single bonded to a carbonyl and single bonded to C
*There is typically a CH3 bonded to the C in the carbonyl
- Ester
75
-thiooate
- Thioester
76
N single bonded to a carbonyl
- Amide
77
-amide
- Amide
78
-oic anhydride
- Carboxylic acid anhyrdide
79
O single bonded to 2 carbonyls
- Carboxylic acid anhydride
80
Carbonyl w/ an -SR' group
- Thioester
81
-phosphate
- Phosphate
82
P double bonded to O and single bonded to 3 Os
*All Os have a negative formal charge (1 bond)
- Phosphate
83
1 phosphate group bonded to another atom
*Depending on O that is bonded to another atom, it will have either a negative (2 bonds) or positive (3 bonds) formal charge.
- Monophosphate
84
2 phosphate groups bonded to each other, w/ one phosphate group bonded to another atom
- Diphosphate
85
-disphosphate
- Diphosphate
86
-triphosphate
- Triphosphate
87
3 phosphate groups bonded to each other, w/ one phosphate group bonded to another atom
- Triphosphate
88
-OPi
- Monophosphate
89
-OPiPi
- Diphosphate
90
-OPP
- Diphosphate
91
-OPPP
- Triphosphate
92
-OPiPiPi
- Triphosphate
93
What is an orbital?
The most probable location to find an electron
94
What is the shape of an s-orbital?
- Sphere
95
What is the shape of a p-orbital?
- Dumbbell
96
What is the shape of a d-orbital?
4-Cloveleaf
97
Which electrons emit lower energy levels?
Electrons closer to the nucleus
98
Which electrons emit higher energy levels?
Electrons farthest the nucleus
99
The prefix for 1
meth-
100
The prefix for 2
eth-
101
The prefix for 3
prop-
102
The prefix for 4
but-
103
The prefix for 5
pent-
104
The prefix for 6
hex-
105
The prefix for 7
hept-
106
The prefix for 8
oct-
107
The prefix for 9
non-
108
The prefix for 10
dec-
109
The ending for alkanes that has a branch
-yl
110
di-
2
111
tri-
3
112
tetra-
4
113
penta-
5
114
What is a cycloalkane
A hydrocarbon ring with C single bonds
115
What is a constitutional isomer?
Molecules that have the same chemical formulas, but different bonds connecting the atoms.
116
"-yl"
Branching
117
What is the first step in naming molecules?
Counting the longest Carbon chain
118
Do molecules with -OH groups have high or low boiling points?
Molecules w/ -OH groups have high boiling points
119
What is bond polarity?
The unequal sharing of e(-) within a covalent bond
120
What does bond polarity lead to?
Charge seperation
Think: H2O (Water)
121
What are non-polar bonds?
Bonds w/ very VERY little charge seperation
122
What are polar bonds?
Polar bonds have some charge seperation
- More electronegative atoms will have a more negative
charge surrounding it. Less electronegative atoms will
have a more positive charge surrounding it.
123
FON
Hydrogen bonds
124
Are hydrogen bonds strong or weak bonds?
Hydrogen bonds are strong dipole-dipole interactions
125
What are the atoms involved in hydrogen bonding?
FON
F - H
O - H
N - H
126
List the intermolecular forces from the strongest to weakest bonds
Strongest: Ionic bonds
Hydrogen bonds
Weakest: Dispersion / London Bridge bonds /
Vanderwaals Interactions
127
What happens to the boiling point as intermolecular forces get stronger?
Boiling point increases
128
Why does the boiling point of a molecule increase as the strength of intermolecular forces increases?
Stronger intermolecular forces require more energy to break. Heat is a form of energy, thus more heat is required to break the strong bonds.
129
What is the relationship between surface area and dispersion forces?
The bigger the surface area, the higher the dispersion forces
130
What happens to the boiling point of a molecule as the number of C increases?
The boiling point increases
131
There are two molecules with the same carbon chain. However, one molecule has branched and the other does not. Out of the two molecules which one will have the higher boiling point?
The molecule without the branching b/c it has a higher surface area than the molecule with branching.
Larger surface area = higher boiling point.
132
What is the relationship between branched molecules and boiling points?
More branching = lower surface area = lower boiling point
133
What is solubility?
The ability of molecules to dissolve in water
134
Hydrophobic
"Water fearing"
Refers to molecules that do not dissolve in water
135
Hydrophilic
"Water loving"
Refers to molecule that dissolve in water
136
What is the polarity of a molecule with no polar bonds?
Nonpolar
137
What is the polarity of C-H bonds?
(For the sake of the class) Nonpolar
138
What is the polarity of a molecule with at least 1 polar bond?
Polar
139
What is the polarity of C-O bonds?
Polar
140
What is the polarity of a molecule that has multiple polar bonds and the bond's bipole movements oppose/cancel out each other?
Hint: Think CF(4)
Nonpolar
141
Terahedron
A molecule w/ 4 bonds
- 1 of the 4 bonds is in the plane of the page (dashes)
- 1 of the 4 bonds is out of the plane of the page (wedge)
142
Draw a tetrahedron molecule
- 2 lines in the plane of the page
- 1 dash
- 1 wedge
143
What is the hybridization of a tetrahedron?
sp^3
144
What is the hybridization of a molecule with double bonds?
sp^2
145
What is the hybridization of a molecule with triple bonds?
sp
146
What is the hybridization of an atom with 4 regions of e- density?
sp^3
- Tetrahedron
147
What is the hybridization of an atom with 3 regions of e- density?
sp^2
148
What is the hybridization of an atom with 2 regions of e- density?
sp
149
What counts as a region of e- density?
Bonds + lone pairs of e-
150
What is conjugation?
When double bonds skip in a continuous array
