Bonding Flashcards
1
Q
What are Ionic Compounds?
A
Oppositely charged ions which are held together by electrostatic attractions.
2
Q
What ion does group one from?
A
1+ ions.
3
Q
What ion does group two form?
A
2+ ions.
4
Q
What ion does group three form?
A
3+ ions.
5
Q
What ion does group five form?
A
3- ions.
6
Q
What ion does group six form?
A
2- ions.
7
Q
What ion does group seven form?
A
1- ions.
8
Q
What is the molecular formula for hydroxide?
A
OH-
9
Q
What is the molecular formula for nitrate?
A
NO3-
10
Q
What is the molecular formula for ammonium?
A
NH4+
11
Q
What is the molecular formula for sulfate?
A
SO4 ^2-
12
Q
What is the molecular formula for carbonate?
A
CO3 ^2-
13
Q
What type of elements does ionic bonds occur between?
A
A metal and a non-metal.
14
Q
What is always the overall charge of an ionic bond?
A
Zero.
15
Q
Can ionic compounds conduct electricity?
A
Only when they are molten or dissolved in a solution.
16
Q
Are the melting points of ionic compounds high or low and why?
A
High as there are many, strong electrostatic forces between oppositely charged ions. There is a lot of energy needed to overcome these forces.
17
Q
Do most ionic compounds dissolve in water and why?
A
Yes because water molecules are polar and can attract the positive and negative ions and break up the structure.
18
Q
What is covalent bonding?
A
The sharing of outer electrons in order for atoms to obtain a full shell.
19
Q
Where is the electrostatic attraction in covalent bonding?
A
Between the shared electrons and the positive nucleus.
20
Q
What is a dative or coordinate bond?
A
Where one atom donates two electrons to an atom or ion to form a bond.
21
Q
What type of elements does covalent bonding occur between?
A
Two non-metals.
22
Q
How is a covalent bond indicated?
A
With a line.
23
Q
How is a dative covalent bond indicated?
A
Using an arrow from the lone electron pair.
24
Q
What are two examples of giant covalent structures?
A
Graphite and Diamond.
25
Describe the structure and properties of graphite.
Each carbon is bonded three times and the fourth electron is delocalised.
There are lots of strong delocalised bonds causing it to have a very high melting point.
It is made up of hexagons.
The layers slide easily.
Able to conduct electricity.
26
What causes graphite to have a very high melting point?
It has lots of strong covalent bonds.
27
What makes the layers in graphite slide easily?
There are weak forces between the layers.
28
What allows graphite to conduct electricity?
Delocalised electrons between the layers as they can carry a charge.
29
What causes a low density in graphite?
It’s layers are far apart in comparison to covalent bond length.
30
Why is graphite insoluble?
The covalent bonds are too strong to break.
31
What shape is diamond?
A tetrahedral shape, created by each carbon bonding four times.
32
What allows diamond to conduct heat well?
It has a tightly packed and rigid arrangement.
33
What gives diamond a very high melting point?
The many strong boiling points as well as it being very hard.
34
Why doesn’t diamond conduct electricity well?
It does not have any delocalised electrons.
35
Why is diamond insoluble?
It’s covalent bonds are too strong to break.
36
What is they key rule of shapes of molecules?
Use the number of bond pairs and lone pairs of electrons to work out the shape of the molecule.
37
Why do molecules have a specific shape with a specific angle?
This is because bonds repel each other equally as they contain electrons which will want to be as far apart as possible.
38
What happens if a lone pair is next to bond pairs?
It will repel further than two bonds together.
39
What is the general rule for lone pairs reducing angles?
The bond angles reduce by 2.5 degrees.
40
What is the name of the shape if it has 2 bond pairs and 0 lone pairs?
Linear.
41
What is the name of the shape if it has 3 bond pairs and 0 lone pairs?
Trigonal Planar.
42
What is the name of the shape if it has 4 bond pairs and 0 lone pairs?
Tetrahedral.
43
What is the name of the shape if it has 5 bond pairs and 0 lone pairs?
Trigonal Bipyramidal.
44
What is the name of the shape if it has 6 bond pairs and 0 lone pairs?
Octahedral.
45
What are the bond angles in a linear molecule?
180 degrees.
46
What are the bond angles in a trigonal planar molecule with 0 lone pairs?
120 degrees.
47
What are the bond angles in a tetrahedral molecule with 0 lone pairs?
109.5 degrees.
48
What are the bond angles in a trigonal bipyramidal with 0 lone pairs?
90 degrees and 120 degrees.
49
What are the bond angles in a octahedral molecule with 0 lone pairs?
90 degrees.
50
What is the name of the shape if it has 3 bond pairs and 1 lone pair?
Pyramidal.
51
What is the name of the shape if it has 2 bond pairs and 2 lone pairs?
Bent.
52
What is the name of the shape if it has 3 bond pairs and 2 lone pairs?
Trigonal Planar.
53
What is the name of the shape if it has 4 bond pairs and 2 lone pairs?
Square planar.
54
What are the bond angles in a pyramidal molecule with 1 lone pair?
107 degrees.
55
What are the bond angles in a bent molecule with 2 lone pairs?
104.5 degrees.
56
What are the bond angles in a trigonal planar molecule with 2 lone pairs?
120 degrees.
57
What are the bond angles in a square planar molecule with 2 lone pairs?
90 degrees.
58
Why does the bond angle in trigonal and square planars not change when there are two lone pairs?
As the lone pairs repel equally from opposite sides.
59
What is meant by electronegativity?
The ability for an atom to attract electrons towards itself in a covalent bond.
60
What is the rule in increasing electronegativity?
The further up and right you go the more electronegative and element is excluding the noble gases.
61
What does the Pauling scale show?
How to quantify how electronegative an element is.
62
How can covalent bonds become polar?
If the atoms attached to it have a difference in electronegativity.
63
What does an increase in the difference in electronegativity in a bond cause?
An increase in how polar the bond is.
64
What two symbols show polarity?
Delta positive and delta negative.
65
Which side of a bond do we put the delta negative symbol if it is polar?
Next to the least electronegative.
66
Which side of a bond do we put the delta positive symbol if it is polar?
Next to the most electronegative.
67
Are hydrocarbons classed as polar or non-polar?
Non-polar.
68
What does an uneven distribution of charges lead to?
Polar Molecules.
69
If a polar bond is arranged symmetrically what is the overall polarity?
Zero.
70
What are Van der Waals forces also known as?
Induced dipole-dipole forces.
71
What is Van der Waals forces also known as?
Induced dipole dipole forces.
72
What do Van der Waals forces occur between?
Atoms and molecules.
73
What are the three key types of intermolecular forces?
Hydrogen bonding,
Permanent dipole-dipole and
Van der Waals.
74
What is the weakest type of intermolecular forces?
Van der Waals.
75
What is the strongest type of intermolecular forces?
Hydrogen bonding.
76
How can any atom or molecule with electrons form a dipole?
By moving near to another atom or molecule, this occurs as electrons in a molecule or atom can move from one end to another creating a temporary dipole.
77
What structure can Van der Waals forces hold some molecules in?
Crystal structures.
78
What increases the strength of Van der Waals forces?
An increase in the size of the molecule or atom as you have larger electron clouds.
79
What are we breaking down when we boil a liquid?
Van der Waals forces.
80
Why do longer, straight chains of hydrocarbons have a higher boiling point?
As they have more Van der Waals forces and this requires more energy to be able to overcome these forces.
81
Why do branched hydrocarbons have lower boiling points?
They can’t pack close together which weakens the Van der Waals forces between the chains.
82
Where do permanent dipole-dipole interactions exist?
In molecules with polarity.
83
If a molecule has dipole-dipole forces what other force does it also have?
Van der Waals forces.
84
When does hydrogen bonding occur?
When you have very electronegative elements.
85
What are the three most electronegative elements which are also the only three elements which hydrogen bond?
Nitrogen, Oxygen and Fluorine.
86
How do you show hydrogen bonds?
Use dotted lines between lone pairs and hydrogen.
87
If a molecule has hydrogen bonding what other intermolecular forces does it also always have?
Van der Waals and Dipole-Dipole.
88
What is formed in metallic bonding?
Giant lattice structures which have positive metal ions as they donate electrons to form a sea of delocalised electrons.
89
Why does magnesium have a higher boiling point than sodium?
It can donate more electrons than sodium as the more electrons an atom can donate to the delocalised system, the higher the melting point.
90
Why are metals good thermal conductors?
The delocalised electrons can transfer kinetic energy.
91
Why are metals good electrical conductors?
The delocalised electrons are mobile and can carry a current.
92
Pent - 1 - ene is formed by the elimination of water from pentan - 2 - ol. State the reagent and conditions for this reaction.
The reagent is concentrated sulfuric acid and the conditions must be hot.
93
Na+ and F- have the same electron configuration, explain why a fluroride ion is larger than a sodium ion.
The fluoride ion has fewer protons and a lower nuclear charge. There is a weaker attraction between the nucleus and the outer electrons.
94
Why is the melting point of sodium fluoride high? Explain in terms of structure and bonding.
There are electrostatic forces of attraction between the oppositely charged ions. Therefore a lot of energy is needed to overcome forces.
95
