Unit 1 Flashcards
(143 cards)
1
Q
metallic bonding
A
high MPs
good conductors of electricity
2
Q
high MPs
good conductors of electricity
A
metallic bonding
3
Q
covalent molecular
A
strong covalent bonds between atoms
weak LDFs between molecules
4
Q
strong covalent bonds between atoms
weak LDFs between molecules
A
covalent molecular
5
Q
covalent network
A
strong covalent bonds between atoms
very high MPs
carbon (as diamond and graphite), silicon, boron
6
Q
strong covalent bonds between atoms
very high MPs
carbon (as diamond and graphite), silicon, boron
A
covalent network
7
Q
what does strong covalent bonds mean for MPs
A
higher MPs
8
Q
monatomic elements
A
nobles gases
weak LDFs
MPs increase as you go down the group
9
Q
LDF strength increases as the ______ __ _______ increases
A
LDF strength increases as the number of electrons increases
10
Q
LDF strength __________ as the number of electrons increases
A
increases
11
Q
what does stronger LDFs mean for MPs
A
higher MPs
12
Q
what should you refer to when comparing MPs
A
bonding, forces
13
Q
what is covalent radius a measure of
A
the size of an atom
14
Q
what is the measurement of the size of an atom
A
the covalent radius
15
Q
what is the covalent radius
A
half the distance between the nuclei of the two covalently bonded atoms of an element
16
Q
half the distance between the nuclei of the two covalently bonded atoms of an element
A
what is the covalent radius
17
Q
going across a period, covalent radius _______
A
decreases
18
Q
going ______ __ _______, covalent radius decreases
A
period
19
Q
going down a group, covalent radius ________
A
increases
20
Q
going _____ __ ______, covalent radius increases
A
down a group
21
Q
going across a period, the nuclear charge ______
A
increases
22
Q
going ______ _ _____, the nuclear charge increases
A
going across a period, the nuclear charge increases
23
Q
going across a period, the nuclear charge ______
A
increases
24
Q
going across a period, the number of filled electron shells _____ ___ _____
A
stays the same
25
going _____ ___ ______, the number of filled electron shells stays the same
across a period
26
what does an increase in nuclear charge mean
electrons being more strongly attracted to the nucleus
--> covalent radius decreases
27
as you go down a group, an extra ___ __ _____ is added
shell of electrons
28
as you go _____ ___ ______, an extra shell of electrons is added
down a group
29
why does covalent radius increase as you go down a group
an extra shell of electrons is added
30
what does an extra shell of electrons is added as you go down a group mean for covalent radius
the covalent radius increases
31
shielding effect
Each extra layer of electrons shields outer electrons from the positive nucleus so that the outer electrons are less strongly attracted to the nucleus
32
Each extra layer of electrons shields outer electrons from the positive nucleus so that the outer electrons are less strongly attracted to the nucleus
shielding effect
33
going down a group, the electronegativity __________
decreases
34
going ______ ____ __ ___, the electronegativity decreases
down a group
35
going across a period, the electronegativity _______
increases
36
going _____ __ _______, the electronegativity increases
across a period
37
what 2 factors influence electronegativity and covalent radius
nuclear charge
number of filled electron shells
38
what does an increase in nuclear charge cause
the atom attracts bonded electrons more strongly
39
the atom attracts bonded electrons more strongly
increase in nuclear charge
40
what happens when the number of filled electron shells increases
outer electrons are further from the nucleus
AND
less strongly attracted to the nucleus
41
outer electrons are further from the nucleus
AND
less strongly attracted to the nucleus
what happens when the number of filled electron shells increases
42
going down a group, the ionisation energy _________
decreases
43
going _____ _ ____, the ionisation energy decreases
down a group
44
going across a period, the ionisation energy _______
increases
45
going ____ __ _____, the ionisation energy increases
across a period
46
covalent bond
atoms share pairs of electrons
two positive nuclei held together by their shared attraction for shared pair of electrons
47
atoms share pairs of electrons
two positive nuclei held together by their shared attraction for shared pair of electrons
covalent bond
48
polar covalent bonds
formed when the attraction of atoms for the pair of bonding electrons is different
49
formed when the attraction of atoms for the pair of bonding electrons is different
polar covalent bonds
50
ionic bonds
the electrostatic attraction between positive and negative ions
51
the electrostatic attraction between positive and negative ions
ionic bonds
52
what do ionic compounds form
lattice structures of oppositely charged ions
53
what compounds forms lattice structures of oppositely charged ions
ionic compounds
54
bonding continuum
pure covalent bonds ----- polar covalent bonds ------ ionic bonding
55
pure covalent bonds ----- polar covalent bonds ------ ionic bonding
bonding continuum
56
the larger the difference in electronegativity, the more ______ the bond will be
polar
57
the larger the difference in _________, the more polar the bond will be
electronegativity
58
what can a large difference in electronegativity cause to form
ions
59
non metal to metal bonding
ionic bonding most of the time
60
is a pure covalent bond polar?
it is non polar
61
van der Waals forces
intermolecular forces acting between molecules
62
LDFs exist between ___ molecules and atoms
all
63
when are LDFs formed
a result of electrostatic attraction between temporary dipoles and induced dipoles caused by movement of electrons in atoms and molecules
64
a result of electrostatic attraction between temporary dipoles and induced dipoles caused by movement of electrons in atoms and molecules
LDFs
65
what are LDF strengths related to
the number of electrons within a molecule or atom
66
when is a molecule described as polar
if it has a permanent dipole
67
pdp to pdp dipole interactions are ____ than LDFs
stronger
68
LDFs are ____ than pdp to pdp dipole interactions
weaker
69
hydrogen bonds are highly ____
polar
70
hydrogen bonds are _____ than other pdp-pdp interactions
stronger
71
hydrogen bonds are stronger than other ______ _______
pdp-pdp interactions
72
hydrogen bonds are ______ than covalent bonds
weaker
73
hydrogen bonds are weaker than ________ _____
covalent bonds
74
the MPs and BPs of polar substances are ______ than that of non polar substances with similar number of electrons
higher
75
the MPs and BPs of ______ substances are higher than that of ______ substances with similar number of electrons
polar, non polar
76
compare the melting points of polar substances with that of non polar substances with similar no. of electrons
polar has higher MPs and BPs than non polar
77
why do hydrogen, water and hydrogen fluoride have unexpectedly high MPs and MPs
because they have hydrogen bonds
78
what effect does hydrogen bonding have on ice
it is an expanded structure that causes ice to have a lower density than water at low temps
79
it is an expanded structure that causes ice to have a lower density than water at low temps
the effect of hydrogen bonds on ice
80
hydrogen bonds and MPs
hydrogen bonds cause substances to have higher than expected MPs and BPs
81
2 features to consider when predicting solubility
1. presence of H-O or N-O bonds (hydrogen bonds)
2. spatial arrangement of polar covalent bonds (could be a permanent dipole)
82
what are ionic compounds held together by in the solid state
ionic bonds
83
LDF are caused by
temporary dipoles
84
pdp pdp are caused by
permanent dipoles
85
weakest type of intermolecular forces
LDFs
86
what are non polar molecules held together by
LDFs
87
what are polar molecules held together by
pdp pdp interactions or hydrogen bonds
88
when are ionic compounds formed
when two atoms bond where there is a large difference in electronegativity
89
what forms when two atoms bond where there is a large difference in electronegativity
ionic compounds
90
what can covalent compounds can be classed as
polar or non polar
91
when are polar covalent bonds formed
when atoms with two atoms with different electronegativity values form a covalent bond
92
what forms when atoms with two atoms with different electronegativity values form a covalent bond
polar covalent bond
93
in a polar covalent bond, which atom is assigned the negative charge
the atom with the higher electronegativity value
94
in a polar covalent bond, what is the the atom with the higher electronegativity value assigned
negative charge
95
in a polar covalent bond, which atom is assigned the positive charge
the atom with the lower electronegativity value
96
in a polar covalent bond, what is the the atom with the lower electronegativity value assigned
positive charge
97
what are the attractions between covalent molecules known as
van der Waals
98
when are non polar covalent bonds formed
when two atoms with the same electronegativity form bonds
99
what bonds form when two atoms with the same electronegativity form bonds
non polar covalent bonds
100
what do symmetrical compounds with polar bonds form
non polar molecules
101
polar molecules are attracted to each other by ____ or ________
pdp pdp or hydrogen bonding
102
non polar molecules are attracted to each other by _____
LDFs
103
when do pdp pdp interactions occur
in molecules with a permanent dipole
104
hydrogen bonds occur between hydrogen and ..
fluorine, oxygen, or nitrogen
105
stronger intermolecular forces means...
higher MPs and BPs
higher viscosity
106
____ dissolves _____
like dissolves like
107
polar substances dissolve in _____ liquids
polar
108
nonpolar substances dissolve in _____ liquids
non polar
109
Why is it important to control the rate of reactions
So that they are….
economically viable (they will result in a good yield of products and profits for the company)
AND
safe (the reaction does not progress too quickly potentially causing explosions).
110
economically viable (they will result in a good yield of products and profits for the company)
AND
safe (the reaction does not progress too quickly potentially causing explosions).
Why is ur important to control rates of reactions
111
As the reactants are used up, what happens to the reactant rate
It will decrease, the reactions slows down
112
Average rate equation
Delta quantity
——————
Delta time
113
Delta quantity
——————
Delta time
Average rate equation
114
Relative rate equation
1
—
T
115
1
——
T
Relative rate
116
Units for reaction rate
S^-1
117
S^-1
Units for reaction rate
118
For a reaction to occur, what must happen
The reactants molecules must collide with enough energy
119
What requires the reactants molecules must collide with enough energy
A chemical reaction
120
Activation energy, Ea
The minimum kinetic energy required for a reaction to occur
121
Why must reactant molecules collide with enough energy
To overcome the repulsive forces (caused by outer electrons)
122
Activated complex
intermediate stage
a high energy, unstable arrangement of atoms
123
An intermediate stage is reached in which a high energy, unstable arrangement of atoms is formed called the activated complex.
Activated complex
124
What is given out when the new product bonds are formed
Energy is given out
125
What happens when new bonds are formed when forming products
(2 points)
Energy is given out
AND
The atoms are rearranged into the product molecules
126
What must happen for a successful collision to occur
The collision geometry must be right
—> the reactants molecules have to be facing the right way
127
what happens to reducing agents
they are oxidised
128
what agents are oxidised
reducing agents
129
electronegativity of reducing agents
low
130
what agents have low electronegativities
reducing agents
131
what agents form positive ions
reducing agents
132
what ions do reducing agents form
positive ions
133
where are the strongest reducing agents
top right of page 12
134
what happens to oxidising agents
they are reduced
135
what agents are reduced
oxidising agents
136
what electronegativity do oxidising agents have
high electronegativity
137
what agents have high electronegativity
oxidising agents
138
what agents form negative ions
oxidising agents
139
what ions do oxidising agents form
negative ions
140
where are the strongest oxidising agents
bottom left of page 12
141
what are found at the bottom left of page 12
strongest oxidising agents
142
143
Symmetry affect on polar bonds
Cancels polarity
