General Review Flashcards
(134 cards)
1
Q
The nucleus contains ______ and ________
A
Protons and neutrons
2
Q
Protons are ______ charged and neutrons are _______
A
Positively charged, neutral
3
Q
How many electrons can each shell contain?
A
2n^2, where n=shell number
4
Q
How many electrons can shell 1 contain?
A
2 electrons
5
Q
How many electrons can shell 2 contain?
A
8 electrons
6
Q
How many electrons can shell 3 contain?
A
18 electrons
7
Q
Shell 3 is _______ in energy than shell 1
A
Higher
8
Q
Why are higher shells higher in energy?
A
Electrons are further away from the nucleus
9
Q
Why are lower shells lower in energy?
A
Electrons are closer to the nucleus
10
Q
What subshells is each shell broken into?
A
s, p, d, and f
11
Q
What does electron configuration describe?
A
The number and position of electrons in orbitals
12
Q
What is the ground state configuration?
A
The lowest energy configuration
13
Q
What rules is ground state determined by?
A
The Aufbau Principle, the Pauli Exclusion Principle, and Hund’s Rule
14
Q
What does the Aufbau Principle state?
A
Orbitals must be filled from lowest energy to highest energy
15
Q
What does the Pauli’s Exclusion Principle state?
A
Only 2 electrons per orbital, and spins must be opposite (spin up with spin down)
16
Q
What does Hund’s Rule state?
A
Add one electron to each orbital equal in energy to minimize electron repulsion
17
Q
Why do we mainly focus on valence electrons?
A
They affect the physical and chemical properties of their atoms and they are involved in bonding
18
Q
What does the octet rule state?
A
Each element is constantly trying to achieve a noble gas configuration (8 electrons in their valence shell)
19
Q
Why do chemical bonds form?
A
Chemical bonds are formed in an attempt to complete an octet and thus achieve noble gas configuration
20
Q
What is a molecule with a net positive electric charge known as?
A
A cation
21
Q
What is a molecule with a net negative electric charge known as?
A
An anion
22
Q
Is sodium (Na) more likely to lose one electron or gain 7 electrons to complete its octet?
A
Lose one electron
23
Q
What other element’s configuration will sodium achieve by losing one electron?
A
Neon
24
Q
Is fluorine more likely to lose 7 electrons or gain 1 electron to complete its octet?
A
Gain one electron
25
What other element's configuration will fluorine achieve by gaining one electron?
Neon
26
What is a covalent bond?
A bond formed by sharing electrons between 1 or more atoms
27
How many electrons do single bonds share?
2 electrons
28
How many electrons do double bonds share?
4 electrons
29
How many electrons do triple bonds share?
6 electrons
30
What are non-binding electrons known as?
Lone pairs
31
What kind of bond is formed when electrons are not shared equally between atoms?
Polar bonds
32
How can one predict the polarity of a particular bond?
Use the periodic table to observe the electronegativity trend (increases from left to right and down to up)
33
What is an ionic bond?
A bond in which electrons are fully transferred
34
What occurs as a result of an ionic bond?
A formal charge
35
1 lone pair = how many regions of electron density?
One region
36
A single bond = how many regions of electron density?
One region
37
A double bond = how many regions of electron density?
One region
38
A triple bond = how many regions of electron density?
One region
39
What is the geometry of a molecule with four regions of electron density spread out over a sphere?
Tetrahedral
40
What is the angle between regions of electron density in a tetrahedral molecule?
109.5 degrees
41
What is the geometry of a molecule with three regions of electron density spread out over a sphere?
Trigonal planar (within the same plane)
42
What is the angle between regions of electron density in a trigonal planar molecule?
120 degrees
43
What is the geometry of a molecule with two regions of electron density spread out over a sphere?
Linear
44
What is the angle between regions of electron density in a linear molecule?
180 degrees
45
What is a resonance structure?
An altered form of a molecule. Two or more valence bond structures of the same molecule.
46
How do electrons move around a molecule?
In clouds of electron density
47
A resonance hybrid depicts ____________.
The actual structure of a compound
48
How does one obtain a resonance hybrid?
Add resonance structures together
49
(T/F) All resonance structures do not have to have the same number of electrons.
False. Resonance structures should contain the same number of electrons regardless of the various structures
50
(T/F) All structures must be valid Lewis structures
True
51
(T/F) Atoms and electrons can move in resonance structures
False. Only electrons can move around a molecule.
52
(T/F) Single and double bonds can be broken in order to move electrons.
False. Only double bonds can be broken. A broken single bond would result in the loss of the original molecule
53
(T/F) The number of unpaired electrons must remain the same
True
54
What are some patterns to determine whether a molecule has resonance (5 patterns)?
1) A lone pair next to a pi bond
2) A lone pair next to a positive charge
3) A pi bond next to a positive charge
4) A pie bond between two atoms (especially when one of the atoms is more electronegative)
5) Pi bonds that go all the way around a ring
55
How can one tell which resonance structure is most important (4 patterns)?
1) Filled valence shell structures contribute more
2) Maximum number of covalent bonds
3) Least separation of unlikely charges (neutral if possible)
4) Negative charge on the more electronegative atom
56
An s orbital has how many defined spaces where electrons can move?
One. S orbitals are spherically shaped, and electrons in this sphere are more likely to be closer to the nucleus
57
A p orbital has how many defined spaces where electrons can move?
Two. P orbitals are bow-tie shaped, and less likely to be found at the nucleus
58
P orbitals exist in _____ dimensions
3. Along the x axis, y axis, and z axis
59
When waves are added, ________ interference occurs
Constructive
60
When waves are subtracted, _______ interference occurs
Destructive
61
When orbitals are in phase, ________ interference occurs
Constructive (addition)
62
When orbitals are out of phase, _________ interference occurs
Destructive (subtration)
63
Sigma star bonds are (higher, lower) in energy than sigma bonds
Higher
64
What is hybridization?
The mixing of orbitals together to get hybrid orbitals with the geometries needed
65
When hybridizing orbitals, the number of atomic orbitals in has to equal ________
The number of atomic orbitals out
66
Tetrahedral molecules use ______ ________ orbitals (how many of what kind of hybridized orbital?)
4 sp3
67
Trigonal planar molecules use ______ ________ orbitals (how many of what kind of hybridized orbital?)
3 sp2
68
Linear molecules use ________ ________ orbitals (how many of what kind of hybridized orbital?)
2 sp
69
What is s character?
The percent of the orbital composed of s orbitals
70
What is the s character of an sp3 orbital?
25%
71
What is the s character of an sp2 orbital?
33.3%
72
What is the s character of an sp orbital?
50%
73
When orbitals are degenerate, they are _______.
Equal in energy
74
What is the hybridization of an atom with 1 region of electron density?
s
75
What is the hybridization and bond angle of an atom with 2 regions of electron density?
sp, 180 degrees
76
What is the hybridization and bond angle of an atom with 3 regions of electron density?
sp2, 120 degrees
77
What is the hybridization and bond angle of an atom with 4 regions of electron density?
sp3, 109.5 degrees
78
Double bonds are composed of __ and __ bonds
Sigma and pi bonds
79
What are pi bonds ALWAYS made of?
Extra p orbitals
80
If a lone pair can be involved in resonance, should it be in a p orbital or remain a lone pair?
In a p orbital
81
Based on overlap, is a pi bond or sigma bond considered a stronger bond?
Sigma
82
Double and triple bonds (lengthen, shorten) a bond length
Shorten
83
The more s character, the (stronger, weaker) the bond
Stronger
84
The shorter the bond, the (stronger, weaker) the bond
Stronger
85
Which bonds can rotate? Which can't?
Single bonds can rotate, double and triple bonds cannot
86
What is a stereoisomer?
Same connectivity, but different orientations in space
87
What is a constitutional isomer?
Same molecular formula, but different connectivity
88
What is a molecular dipole?
The vector sum of bond dipoles
89
What is an ion ion force?
The strong electrostatic force between positive and negative ions
90
As a result of ion ion forces, molecules have (high, low) _____ melting points and (high, low) boiling points
High, high
91
What are the 3 kinds of Van der Waals forces?
1) Dipole-dipole
2) Hydrogen bonds
3) Dispersion forces
92
Dipole-dipole forces originate from the fact that _______________________________.
Some molecules have permanent dipoles (are polar). These molecules orient so that the positive of one molecule interacts with the negative of another
93
Dipole-dipole forces cause molecules to have (higher, lower) boiling points vs. not having this interaction
Higher
94
Define the hydrogen bond force.
Strong interaction between a heteroatom with hydrogen and a heteroatom with a lone pair
95
Hydrogen bonds are (stronger, weaker) than covalent bonds
Weaker
96
Hydrogen bonds are (stronger, weaker) than dipole-dipole forces
Stronger
97
The more hydrogen bonds, the (higher, lower) the boiling point
Higher
98
What are dispersion forces?
Forces that arise from the interactions based on temporary induced dipoles
99
What is the weakest interaction between molecules?
Dispersion forces
100
Dispersion forces produce attractive forces between ________ molecules
Nonpolar
101
Smaller molecules experience (more, less) attraction than large molecules. Why?
Less. Larger molecules have more surface area, and thus can experience more attraction
102
Branching (increases, reduces) boiling point
Reduces
103
Why does branching reduce boiling point?
There is less surface area (think in terms of large vs. small molecules)
104
(T/F) Polar dissolves non-polar
False. Polar dissolves polar, non-polar dissolves non-polar
105
Why doesn't water dissolve in oil?
It would cost a lot of energy to break the hydrogen bonding of water to mix with something that cannot provide that interaction
106
Ions dissolve well in _______ and a few other _____ solvents
Water and a few other polar solvents.
107
What does it mean if a molecule is capable of solvating?
It is capable of encapsulating an ion
108
Polar and ionic solids usually dissolve in ______ solvents
Polar
109
Polar liquids are _________
Miscible (fully mixable)
110
Non-polar solids are soluble in ________ solvents
Non-polar
111
Non-polar liquids are _______
Miscible (fully mixable)
112
What is the label for a molecule that is incompatible for water?
Hydrophobic
113
What is the label for a molecule that is compatible with water?
Hydrophilic
114
Can molecules contain both hydrophilic and hydrophobic regions within itself?
Yes
115
In a Bronsted Lowry acid base reaction, the Bronsted acid acts as the proton (donor, acceptor)
Donor
116
In In a Bronsted Lowry acid base reaction, the Bronsted base acts as the proton (donor, acceptor)
Acceptor
117
What is a mechanism?
A description of the events that take place as reactants become products
118
How can we describe what's going on with electrons and hydrogens?
Arrow pushing
119
What if a base has 2 or more possible acceptors?
Use resonance structures to find out which acceptor will actually accept the proton
120
How do we tell how strong an acid is?
pKa
121
How does one calculate Keq?
[products]/[reactants]
122
Ka=?
[A-][H3O+]/[HA]
123
pKa=?
-log(Ka)
124
When molecules contain the same functional groups, their pKa's will be (approximately equal, different)
Approximately equal
125
Equilibrium lies towards the (stronger, weaker) acid
Weaker
126
A stable anion is (more, less) acidic
More
127
What are the ways to stabilize an anion (5 ways)?
1) Electronegative atom
2) Larger atom
3) Resonance stabilized
4) Induce electron withdrawing group
5) Hybridization
128
As electronegativity of an atom increases, acidity (increases, decreases)
Increases
129
(T/F) Size is better for handling a negative charge
True. Larger surface area is able to distribute the charge more
130
(T/F) Resonance makes molecules less acidic
False. Resonance allows two atoms to share the negative charge, and this is a stabilizing effect. Stable atoms=more acidic molecules
131
(T/F) The help that induction provides increases with distance
False. The help that induction provides decreases rapidly with distances
132
(T/F) Molecules with higher s character are more acidic
True. Think in terms of hybridized orbitals:
sp3: 25% s character, electrons not as close to nucleus
sp2: 33.3% s character
sp: 50% s character, electrons help tighter to nucleus, stabilizing effect
133
What 5 strong acids should you have memorized?
H3PO4, H2SO4, HCl, HBr, HI
134
How do Lewis acids and bases differ from Bronsted acids and bases?
Lewis acids act as the electron acceptor, and Lewis bases act as the electron donor. Both form covalent bonds
