C3. Bonding Flashcards

1
Q

What effect do lone pairs have on bond angles?

A

Greater repulsion than bonding pairs, lone pairs have 2.5 degree effect on bond angles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the different types of bonding?

A

Ionic, Covalent, Metallic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is ionic bonding?

A

Electrostatic attraction between positive and negative ions in a lattice

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What substances can an ionic bond exist between?

A

Metal - non metal ions; hydrogen - non metal ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the properties of ionic compounds?

A

Crystalline solids, high melting and boiling points, soluble in water, conduct electricity as molten or aq, hard and brittle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Why do ionic structure have high melting and boiling points?

A

Large amount of energy required to overcome large number of strong electrostatic forces between ions in lattice

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Why are ionic substances soluble in water?

A

+ and - dipoles in water are attracted to ions and pull lattice apart, energy is required (endothermic)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Why are ionic compounds hard and brittle?

A

Strong electrostatic forces holding lattice together, when struck, ions with like charge align and repel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is a covalent bond?

A

Shared pair of electrons which are attracted to the nuclei in each atom

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What substances can a covalent bond exist between?

A

Non metal atoms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is a discrete covalent bond?

A

Small group of atoms held by strong covalent bond and weak intermolecular forces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is a giant covalent bond?

A

3D structure held together by covalent bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the general properties of covalent bond?

A

Low melting and boiling points, no electrical conductivity, insoluble in water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is a dative covalent bond?

A

Covalent bond where both electrons come from same atom

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How do you show a dative covalent bond in a diagram?

A

Arrow point from donating atom to receiving atom

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is metallic bonding?

A

Valence electrons can move from one atom to another creating a cloud of delocalized electrons. The positive metal ions are immersed in this cloud. Electrostatic interactions are responsible for the metallic bond.
Metallic bonding joins a bulk of metal atoms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the physical properties of metals?

A

High density, high melting and boiling point, electrical conductivity, thermal conductivity, malleable, ductile

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Why do metals have high melting and boiling points?

A

Many strong electrostatic forces hold lattice together, lots of energy required to overcome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Why can metals conduct electricity?

A

Delocalised electrons move randomly through lattice of positive ions, potential difference connected, carrying charge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Why do metals conduct heat?

A

Electrons bump into ions in cooler regions to transfer energy, vibration of tightly packed metal ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Why are metals malleable and ductile?

A

No rigid bonds between lattice layers, atom layers can slide

22
Q

What are examples of giant covalent structures?

A

Diamond, Graphite, Ice, Iodine

23
Q

What is an example of a giant metallic structure?

A

Magnesium

24
Q

What is an example of a giant ionic structure?

A

Sodium chloride

25
Q

What are the properties of iodine?

A

Atoms are big so many weak Van der Waals forces ; macromolecular lattice; small amount of heat energy to overcome forces; hence sublimation

26
Q

What are the properties of ice?

A

Covalent bonds between O & H; solid state hydrogen bonding between water molecules, 3D lattice; intermolecular hydrogen bonds are weak, low energy to overcome attractive forces ; Water low melting and boiling points

27
Q

What are the properties of diamond?

A

Hard, high melting and boiling point. each atom 4 covalent bonds, no electrical conductivity

28
Q

What are the properties of graphite?

A

High melting and boiling point, soft flaky, layers can slide over each other due to weak Van der Waals forces, electrical conductivity, carbon bonded to 3, 1 free delocalised electron

29
Q

What are the properties of magnesium?

A

High melting and boiling point, Electrostatic attraction between metal ions and delocalised electrons, strong giant metallic lattice

30
Q

What are the properties of sodium chloride?

A

High melting and boiling point, electrostatic attraction between + ions and - ions, strong giant ionic lattice

31
Q

What is electronegativity?

A

Power of an atom to attract the electron density in a covalent bond towards itself

32
Q

How is electronegativity measured?

A

Pauling scale 0 - 4 (4 most electronegative)

33
Q

What are the factors that increase electronegativity and why?

A

Smaller atoms, bonding electrons to nucleus ; Larger nuclear charge, greater attraction for bonding electron; Less shielding, greater attraction between nucleus and bonding electron

34
Q

What are the electronegativity trends across a period?

A

Electronegativity increases - same shielding , decreasing atomic radius, increasing nuclear charge

35
Q

What are the electronegativity trends down a group?

A

Electronegativity decreases - shielding and distance from nucleus increases

36
Q

What is the most electronegative element?

A

Fluorine , Pauling scale 4.0

37
Q

What is bond polarity?

A

Unequal sharing of electron density as result of difference in electronegativity

38
Q

What are different types of intermolecular forces (ascending order) ?

A

Van der Waals forces, Permanent dipole-permanent dipole, hydrogen bonds

39
Q

What are the properties of Van der Waals forces?

A

1/1000 of covalent bond,Weakest IMF, due to momentary dipoles, exist for moments, increases boiling point

40
Q

How do intermolecular forces affect alkane structures?

A

Straight chain alkane, pack closer together, more points of contact between molecules, stronger Van der Waals forces

41
Q

What are the properties of permanent dipole-permanent dipoles?

A

1/100th of covalent bond; polar molecules, permanent dipoles;

42
Q

What are the properties of hydrogen bonding?

A

1/10th of covalent bond; Positive hydrogen strongly attracted to lone pairs of N O F, highly electronegative, strong permanent dipole-dipole forces

43
Q

What shape and angle does 2 electron pairs create?

A

Linear, 180

44
Q

What shape and angle does 3 electron pairs create?

A

Trigonal planar, 120

45
Q

What shape and angle does 4 electron pairs create?

A

Tetrahedral, 109.5

46
Q

What shape and angle does 5 electron pairs create?

A

Trigonal bipyramidal, 90, 120

47
Q

What shape and angle does 6 electron pairs create?

A

Octahedral, 90

48
Q

What shape and angle does 2 electron pairs and 2 lone pairs create?

A

Bent, 106.5

49
Q

What shape and angle does 3 electron pairs and 1 lone pairs create?

A

Triangular pyramidal, 107

50
Q

What shape and angle does 4 electron pairs and 2 lone pairs create?

A

Square planar, 120