Exam 2 Flashcards
1
Q
fixed charges
A
group 1 & 2; Al 3+, Ga 3+, Zn 2+, Cd 2+, Ag+
2
Q
transition metals lose __ e- first
A
ns
3
Q
p-block loses _ e- first
A
p
4
Q
d-block loses __ e- first
A
s
5
Q
e- configuration of Mn vs Mn +2
A
4s2 3d5
Mn +2: 3d5
6
Q
e- configuration of Cu vs Cu +2
A
4s1 3d10
Cu +2: 3d9
7
Q
e- configuration of In vs In +1 vs In +3
A
5s2 5p1
In +1: 5s2
In +3: lost whole shell (NT)
8
Q
what are the potential charges for Sn
A
Sn: 5s2 5p2
+2 and +4
9
Q
what are the potential charges for Pb
A
+2 and +4
Pb: 6s2 6p2
10
Q
what are the potential charges for Sb
A
+3 and +5
Sb: 5s2 5p3
11
Q
anion is __ than atom
A
larger
12
Q
cation is __ than atom
A
smaller
13
Q
lewis dot formula
A
A formula using dots to represent valence electrons
14
Q
octet rule
A
In forming covalent bonds, atoms tend toward having a full eight electrons in their valence shell
*H is exception bc it has two electrons in its valence shell.
15
Q
ionic radius
A
a measure of the size of the spherical region around the nucleus of an ions within which the e- are most likely to be found
- can be measured using known distances between nuclei in crystals
16
Q
isoelectric
A
different species having the same number and configuration of electrons.
17
Q
organize the following isoelectronic series in decreasing order:
F-, O 2-, Mg +2
A
O 2-, F-, Mg +2
18
Q
bond length
A
The distance between the atoms when energy is at a minimum
19
Q
polar covalent bond
A
a covalent bond in which the bonding electrons spend more time near one atom than near the other atom.
20
Q
what elements have the highest electronegativity?
A
Cl, F, O, N
21
Q
what are the 3 exceptions to lewis dot diagrams
A
- odd # of e-
- too few e-
- too many e-
22
Q
example of having an odd # of e-
A
NO (11)
- not stable
23
Q
example of having too few e-
A
Be, Al, B
- Be forms 2 bonds
- Al and B form 3 bonds
24
Q
example of having too many e-
A
XeF4
8 + 4(7) = 36 e-
25
formal charge
group # - # of bonds - # of lone pair e-
26
electronegativity
a measure of the ability of an atom in a molecule to draw bonding electrons to itself.
27
single bond
a covalent bond in which one pair of electrons is shared by two atoms.
28
double bond
a covalent bond in which two pairs of electrons are shared by two atoms.
*Double bonds form primarily with C, N, O, and S atoms.
29
triple bond
a covalent bond in which three pairs of electrons are shared by two atoms.
*Triple bonds form primarily with C and N atoms.
30
rules for formal change
1. Half of the electrons of a bond are assigned to each atom in the bond.
2. Both electrons of a lone pair are assigned to the atom to which the lone pair belongs.
31
resonance
the electron structure of a molecule or ion having delocalized bonding is given by writing all possible electron-dot formulas. They are connected with a double-headed arrow.
32
expanded octet
periods 3,4, 5,... non-metals
| *P, S
33
bond order
```
# of pairs of e- in a bond
*larger the bond order, shorter the bond length
```
34
bond length
distance between nuclei in a bond
35
which is the shortest: C-C, O=O, N≡N
N≡N
36
bond energy
energy it takes to break a bond
- can be used to measure ∆H
- break multiple bonds to get a single bond
37
```
2 H2 (g) + O2 (g) -> 2 H2O (g)
using the chart, find the ∆H
```
-482 kJ
38
VSEPR
valence shell electron pair repulsion model
39
molecular geometry
general SHAPE of a molecule
40
arrangement
all e- regions
41
shape
bonding regions
42
region
1 lone pair, 1 single bond, 1 double bond, 1 triple bond
43
2 e- pairs are __ apart
180º (linear)
44
3 e- pairs are __ apart
120º (trigonal planar)
45
4 e- pairs are __ apart
109.5º (tetrahedral)
46
5 e- pairs are arranged with 3 pairs __ and 2 pairs __ and __ to each other
120º; 90º and 180º (trigonal bipyramidal)
47
6 e- pairs are __ apart
90º (octahedral)
48
total number of valence e- in BeCl2
16
49
total number of valence e- in NO2-
18
50
lone pairs in 5 e- pairs are
equitorial
51
what is the shape of TeCl4?
trigonal bipyramid
| *see-saw arrangement
52
what is the shape of SF4?
trigonal bipyramid
53
what is the geometry of XeF2?
linear
| *arrangement: trigonal bipyramid
54
arrangment
looks at ALL regions
55
shape/geometry
starts with arrangement and omits lone pairs (only uses bonds)
56
what is the geometry of IF5?
square pyramidal
57
predicting bond angles: 180º
linear
58
predicting bond angles: 120º
trigonal planar
59
predicting bond angles: 109.5º
tetrahedral
60
lone pairs push __ closer together and tend to require more space than corresponding pair
bonds
61
lone pairs tend to __ bond angle
reduce
62
double bonds require __ space than single bonds & cause bond angle to constrict/reduce
more
63
dipole moment
a quantitative measure of the degree of charge separation in a molecule
- dipole moment of a molecule can affect its properties
- indicator of polarity on molecule
64
are diatomic molecules polar or non-polar?
non-polar
65
is CO2 polar or non-polar?
the bonds are polar, the molecule is non-polar
66
is SO2 linear or bent?
bent
67
is PH3 trigonal planar or trigonal pyramid?
trigonal pyramid
68
molecular geometry of AX
linear
69
molecular geometry of AX2
linear, bent
70
molecular geometry of AX3
trigonal planar, trigonal pyramidal, T-shaped
71
molecular geometry of AX4
tetrahedral, square planar, seesaw
72
molecular geometry of AX5
trigonal bipyramidal, square pyramidal
73
molecular geometry of AX6
octahedral
74
cis- vs trans-
cis- is on the same side of double bond
| trans- opposite side of double bond
75
valence bond theory
an approximate theory put forth to explain the electron pair or covalent bond by quantum mechanics
76
_ hybrid orbital is required for each bond and for each lone pair
1
77
hybrid orbitals
orbitals used to describe the bonding obtained by taking combinations of the atomic orbitals of the isolated atoms
- number of hybrid orbitals formed always equals the number of atomic orbitals used
78
kinds of hybrid orbitals
of orbitals: hybrid orbitals: geometric arrangement:
2 sp linear
3 sp2 trigonal planar
4 sp3 tetrahedral
5 sp3d trigonal bipyramid
6 sp3d2 octahedral
79
a multiple bond can form by the overlapping of more than _ orbital from each bonding atom
1
80
of hybrid orbitals =
of atomic orbitals
81
what is the hybridization of H2O
sp3
| - sigma bond
82
is C2H4 a pi bond or sigma bond?
pi bond
83
sigma bond
has a cylindrical shape about the bond axis
- formed either when two s orbitals overlap or with directional orbitals (p or hybrid) when they overlap along their axis
84
pi bond
has an electron distribution above and below the bond axis
- formed by the sideways overlap of 2 parallel p orbitals
- this overlap occurs when 2 parallel half-filled p orbitals are available after sigma bonds have formed
85
formal charge
VE - LE - BE/2
OR
VE- LE - bonds
86
draw the best lewis structure for SO2. show electron counts and formal charge on each atom and complete the following:
- number of valence e-
- formal charge of S
- formal charge of O
- hybridization of S
- is the molecule polar?
- is the dipole moment zero?
- 18 e-
- formal charge of S: 0
- formal charge of O: 0
- hybridization: sp2
- the molecule is polar
- the dipole moment is zero
87
which element goes in the middle for lewis structures?
the least electronegative one
88
molecular orbital theory
- current best theory
- theory of electronic structure of molecules in terms of molecular orbitals, which may spread over several atoms or the entire molecule
- sigma σ
- pi π
- as atoms approach one another, their atomic orbitals overlap and form molecular orbitals
- can describe delocalized bonding in terms of a single e- configuration
89
sigma bonding orbital
1s + 1s --> attraction
- most bonding is between atoms
- high e- density
90
sigma anti-bonding orbital
1s - 1s -> repulsion
- not between atoms
- low e- density
91
bond order formula
B.O.: 1/2 (nb- na)
nb: e- bonding orbital
na: e- anti bonding orbital
92
what is the molecular orbital of H
.
93
bond order of H2
1
94
bond order of He2
0
95
bond order of Li
1
96
strength of bond is determined by
1) energy difference between interacting orbitals
2) magnitude of overlap
- energies of the 2 orbitals must be approximately equal and the overlap must be large
97
2 diff ways in which 2p orbitals interact
1) one set of 2p orbitals can overlap along their axes to give one bonding and one anti bonding orbital *σ orbitals
2) other 2 sets of 2p orbitals then overlap sideways to give 2 bonding and 2 anti bonding π orbitals
98
bond order of NO
2.5
99
bond order of NO+
3
100
bond order of O2 +
2.5
101
bond order of O2
2
102
bond order of O2-
1.5
103
which one is longer, O2 + or O2
O2
104
which one is longer, O2 or O2 -
O2 -
105
the lower the bond order, the __ the bond is for the same 2 atoms
longer
106
is oxygen diamagnetic or paramagnetic?
paramagnetic
| - has 2 unpaired e-
107
C2H2
H - C ≡ C - H
- determine hybridization
- determine sigma vs pi bond
1,2 H 1s, C sp -> σ bond
3 C sp, C sp -> σ bond
4 C 2p, C 2p -> π bond
5 C 2p, C 2p -> π bond
108
arrangement of e- pairs
```
linear
trigonal planar
tetrahedral
trigonal bipyramidal
octahedral
```
109
arrangement of e- pairs and shape of a molecule with 2 total e- pairs (2 bonding e- pairs, and 0 lone e- pairs)
arrangement: linear
shape: linear
110
arrangement of e- pairs and shape of a molecule with 3 total e- pairs (3 bonding e- pairs and 0 lone e- pairs)
arrangement: trigonal planar
shape: trigonal planar
111
arrangement of e- pairs and shape of a molecule with 3 total e- pairs (2 bonding e- pairs and 1 lone e- pair)
arrangement: trigonal planar
shape: bent
112
arrangement of e- pairs and shape of a molecule with 4 total e- pairs (4 bonding e- pairs and 0 lone e- pairs)
arrangement: tetrahedral
shape: tetrahedral
113
arrangement of e- pairs and shape of a molecule with 4 total e- pairs (3 bonding e- pairs and 1 lone e- pair)
arrangement: tetrahedral
shape: trigonal pyramidal
114
arrangement of e- pairs and shape of a molecule with 4 total e- pairs ( 2 bonding e- pairs and 2 lone e- pairs)
arrangement: tetrahedral
shape: bent
115
arrangement of e- pairs and shape of a molecule with 5 total e- pairs (5 bonding e- pairs and 0 lone e- pairs)
arrangement: trigonal bipyramidal
shape: trigonal bipyramidal
116
arrangement of e- pairs and shape of a molecule with 5 total e- pairs (4 bonding e- pairs and 1 lone e- pair)
arrangement: trigonal bipyramidal
shape: see saw
117
arrangement of e- pairs and shape of a molecule with 5 total e- pairs (3 bonding e- pairs and 2 lone e- pairs)
arrangement: trigonal bipyramidal
shape: T-shaped
118
arrangement of e- pairs and shape of a molecule with 5 total e- pairs (2 bonding e- pairs and 3 lone e- pairs)
arrangement: trigonal bipyramidal
shape: linear
119
arrangement of e- pairs and shape of a molecule with 6 total e- pairs (6 bonding e- pairs and 0 lone e- pairs)
arrangement: octahedral
shape: octahedral
120
arrangement of e- pairs and shape of a molecule with 6 total e- pairs (5 bonding e- pairs and 1 lone e- pair)
arrangement: octahedral
shape: square pyramidal
121
arrangement of e- pairs and shape of a molecule with 6 total e- pairs (4 bonding e- pairs and 2 lone e- pairs)
arrangement: octahedral
shape: square planar
122
de Broglie Rxn
```
λ = h / mv
λ = wavelength (m)
h = planck's constant (J x s)
v = velocity (m/s)
```
123
commonly used prefixes in metric system
prefix symbol meaning power of 10
giga G 10^9
mega M 1,000,000 10^6
kilo k 1000 10^3
deci d 0.1 10^-1
centi c 0.01 10^-2
milli m 0.001 10^-3
micro μ 0.000001 10^-6
nano n 0.000000001 10^-9
pico p 10^-12
124
rules for sig figs
1) all nonzero integers ALWAYS count for significance ex: 3456 has 4 sig figs
2) zeros (3 classes of zeros)
a) leading zeros:NEVER count as sig figs
ex: 0.048 has 2 sig figs
b) captive zeros: ALWAYS count as sig figs ex: 16.07 has 4 sig figs
c) trailing zeros: only significant when # HAS A DECIMAL POINT
ex: 9.300 has 4 sig figs; 0.004020 has 4 sig figs; 150 has 2 sig figs
125
how to find ∆H
of bonds broken - # of bonds formed
126
Explain the impact on bond order when an electron is removed (a) and added (b).
For N2,
When an electron is removed, it is removed from a bonding orbital, giving a lower bond order, making the bond weaker and longer.
When an electron is added it goes into an antibonding orbital, also giving a lower bond order. making the bond weaker and longer.
127
which has a higher boiling point, polar or non-polar molecules?
polar
128
a molecule is considered to be polar when the electronegativity difference is at least __
0.5
129
magnetic properties
- paramagnetic substance: weakly attracted; unpaired e-
| - diamagnetic substance: only paired e-
130
bonding
forms a bond, there is a signification e- density between 2 nuclei ( σ)
131
anti-bonding
there is no e- density between 2 nuclei ( σ*)
132
exceptions for less than octet
Be, B, Al
133
exceptions for expanded octet
S, P, Si, and Cl
