1.8 & 1.9 : Covelant Bonding Flashcards

1
Q

What 5 factors favour covelant bonding?

A
  • High ionization energies
  • Equal electron affinities
  • Equal/similar electronegativity
  • High nuclear charge
  • Small atomic size
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Define “lone pair of electrons”

A

A pair of electrons in the valence shell of the atom
that are not involved in bonding

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

What is a dative (co-ordinate) covelant bond?

A

Bond where both shared electrons come from one atom/ion.

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

What are the conditions for dative covelat bond formation?

A
  • Donating atom must have a lone pair of
    electrons
  • Accepting atom should have a vacant
    orbital to accept the electron pair donated by the donor
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Learn slide 19

A

Dative bonding in biology

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

The unction of some drugs depends on their ability to:

A

*act as donors in dative covalent bonds – chelation therapy
* act as acceptors for biological donors

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

Learn Slide 20 examples

A

Drugs

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

Which Theory is used to predict the structure of simple covelantly bonded molecules and ions?

A

Valence Shell Electron Pair Repulsion theory
(VSEPR)

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

What is the characteristic of the 3D shape of a simple molecule/ ion?

A

Keep repulsive forces to a minimum - electron pairs stay as far apart as possible

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

What do we use to predict the shape of a molecule?

A

Number of electron pairs

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

Describe a molecule with 2 bond pairs

A

• Linear shaped
• 180° bond angles

Example: BeCl2

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

Describe a molecule with 3 bond pairs

A

• Trigonal planar shape
• 120° bond angles

Examples: AlCl3

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

Describe a molecule with 4 bond pairs

A

• Tetrahedral shaped
• 109.5° bond angles

Example: CH4

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

Describe a molecule with 5 bond pairs

A

• Trigonal Bipyramidal shape
• 90° AND 120° bond angles

Example: PCl5

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

Describe a molecule with 6 bond pairs

A

• Octahedral shape
• 90° bond angles

Example: SF6

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

Describe molecule with:
2 bond pairs
1 lone pair

A

• 3 electron domains
• Domain geometry = trigonal planar
• Molecule geometry = Bent linear

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

Describe molecule with:
1 bond pair
2 lone pairs

A

• 3 electron domains
• Domain geometry: Trigonal planar
• Molecule geometry: Linear

18
Q

Describe molecule with:
3 bond pairs
1 lone pair

A

• 4 electron domains
• Domain geometry: Tetrahedral
• Molecular geometry: Pyramidal

19
Q

Describe molecule with:
2 bond pairs
2 lone pairs

A
  • 4 electron domains
  • Domain geometry: Tetrahedral
  • Molecular geometry: Bent linear
20
Q

Describe molecule with:
1 bond pair
3 lone pairs

A
  • 4 electron domains
  • Domain geometry: Tetrahedral
  • Molecular geometry: Linear
21
Q

How many degrees does each lone pair decrease bond angles?

A

2 degrees

22
Q

Describe molecule with:
4 bond pairs
1 lone pair

A
  • 5 electron domains
  • Domain geometry: Trigonal bipyramid
  • Molecular geometry: Seesaw
23
Q

Describe molecule with:
3 bond pairs
2 lone pairs

A
  • 5 electron domains
  • Domain geometry: Trigonal bipyramid
  • Molecular geometry: T-shaped
24
Q

Describe molecule with:
2 bond pairs
3 lone pairs

A
  • 5 electron domains
  • Domain geometry: Trigonal bipyramid
  • Molecular geometry: Linear
25
Q

Describe molecule with:
5 bond pairs
1 lone pairs

A
  • 6 electron domains
  • Domain geometry: Octahedral
  • Molecular geometry: Square pyramidal
26
Q

Describe molecule with:
4 bond pairs
2 lone pairs

A
  • 6 electron domains
  • Domain geometry: Octahedral
  • Molecular geometry: Square planar
27
Q

Describe molecule with:
3 bond pairs
3 lone pairs

A
  • 6 electron domains
  • Domain geometry: Octahedral
  • Molecular geometry: T-shaped (theoretical)
28
Q

Describe molecule with:
2 bond pairs
4 lone pairs

A
  • 6 electron domains
  • Domain geometry: Octahedral
  • Molecular geometry: linear
29
Q

What bond angle do linear molecules still have?

A

180 degrees

30
Q

What does no difference in electronegativity between two atoms lead to?
Example?

A

Pure non-polar covelant bonds

Cl-Cl

31
Q

What does a small difference in electronegativity between two atoms lead to?
Example?

A

Polar covelant bonds

C-Cl

32
Q

What do polar bonds affect?

A

Reactivity of the bond and types of intramolecular forces between molecules

33
Q

What does a large difference in electronegativity between two atoms lead to?
Example?

A

Ionic bonds

NaCl

34
Q

How can one determine if a molecule not polar?

A

The bonds wont be polar

35
Q

What happens to opposing dipoles? What is the overall polarity of the molecule?

A

Opposing dipoles cancel
No net dipole movement - not polar

36
Q

What are the properties of Giant Covelant Structure?

A
  • Contain many atoms
  • Can be similar to an ionic lattice
  • Properties depend on structure
37
Q

Give 4 examples of giant ionic structures

A
  1. Diamond
  2. Silicon Dioxide
  3. Graphite
  4. Carbon nanotube
38
Q

Compare state in covelant and ionic compounds

A

Covelant - Solid, liquids and gases
Ionic - Crystalline solids

(Note: There are many counterexamples but most compounds obey these rules)

39
Q

Compare melting and boiling points of covelant and ionic compound

A

Covelant - Depends on size and intermolecular bonding
Ionic - High

(Note: There are many counterexamples but most compounds obey these rules)

40
Q

Compare conductivity of covelant and ionic compounds

A

Covelant - Often poor. Depends on size and delocalisation of electrons

Ionic - Good when molten

(Note: There are many counterexamples but most compounds obey these rules)

41
Q

Compare solubility of covelant and ionic compounds

A

Covelant - Depends on intermolecular bonding

Ionic - Many soluble in water but not in non-polar solvents

(Note: There are many counterexamples but most compounds obey these rules)