Flashcards in Chapter 10: Chemical Bonding II: Molecular Shapes, Valence Bond Theory, and Molecualr Orbital Theory Deck (61):

1

## Define electron groups

### A general term for lone pairs, single bonds, multiple bonds, or lone electrons in a molecule

2

## According to VESPR theory what do the repulsions between electron groups on interior atoms of a molecule determine?

### The geometry of the molecule

3

## The preferred geometry of a molecule is the one which electron groups have the _____ separation (and therefore _____ energy) possible

###
Maximum

Minimum

4

## For molecules that have just one interior atom (the central atom), what two things does the the molecular geometry depend on?

###
1. The number of electron groups around the central atom

2. How many of those electron groups are bonding groups and how many are lone pairs

5

## What is the electron geometry for two electron groups?

### Linear geometry

6

## What are the angles between the two electron group in linear geometry

### 180°

7

## Is a double bond still one electron group?

### Yes

8

## Linear geometry can be observed in all molecules that have....

### Two electron groups and no lone pairs

9

## What electron geometry forms with 3 electron groups?

### Trigonal planar

10

## What angle for trigonometry planar geometry maximizes the electron groups separation?

### 120°

11

## Electron geometry, the geometry predicted by VESPR theory, is ______

###
Idealized

(This means that it is close but not the same as the geometry found experimentally)

12

## What is the electron geometry for four electron groups?

### Tetrahedral geometry

13

## What are the ideal angles of tetrahedral geometry?

### 109.5°

14

## What is the geometry for five electron groups?

### Trigonal bipyramidal geometry

15

## What are the angles like for trigonal bipyramidal geometry?

### The angles between the equatorial positions (the three bonds in the trigonal plane) are 120°, while the angle between the axial positions (the two bonds on either side of the trigonal plane) and the trigonal plane is 90°

16

## What is the electron geometry for 6 electron groups?

###
Octahedral geometry

17

## Define valance shell electron pair repulsion theory (VSEPR theory)

### A theory that allows prediction of the shapes of molecules based on the idea that electrons—either as lone pairs or bonding pairs—repel one another

18

## What are the angles for octahedral geometry?

### All angles are 90°

19

## Define electron geometry

### The geometrical arrangement of electron groups in a molecule

20

## Define molecular geometry

### The geometrical arrangement of atoms in a molecule

21

## Lone pairs take up ____ than bonding pairs

### More

22

## What is the molecular geometry of a molecule with 4 electron groups, with one of them being a lone pair?

### Trigonal pyramidal

23

## What is the molecular geometry of a molecule with 4 electron groups, with two of them being a lone pairs?

### Bent

24

## Lone pair–lone pair repulsion is _____ than lone pair–bonding pair repulsion which is _____ than bonding pair–bonding pair repulsion

###
Greater

Greater

25

## Lone pairs ____ occupy axial positions

### Never

26

## What is the molecular geometry of a molecule with 5 electron groups, with one of them being a lone pair?

### Seesaw

27

## What is the molecular geometry of a molecule with 5 electron groups, with two of them being a lone pairs?

### T-shaped

28

## What is the molecular geometry of a molecule with 5 electron groups, with three of them being a lone pairs?

### Linear

29

## What is the molecular geometry of a molecule with 6 electron groups, with one of them being a lone pair?

### Square pyramidal

30

## What is the molecular geometry of a molecule with 6 electron groups, with two of them being a lone pairs?

### Square planar

31

## How can you determine the number of electron groups

### From the Lewis structure

32

##
A straight line is....?

A hashed wedge is...?

A solid wedge is...?

###
Bond in the plane of the paper

Bond going into the page

Bing coming out of the page

33

## If a diatomic molecule has a polar bond, is the whole molecule polar?

### Yes

34

## If the bond in a diatomic molecule is nonpolar, the molecule as a whole will be ______

### Nonpolar

35

## If the molecular geometry is such that the dipole moments of idividual polar bonds sum together to a net dipole moment the the molecule will be ____

### Polar

36

## It the molecular geometry is such that the dipole moments of the individual polar bonds cancel each other (that is, sum to zero), then the molecule will be _____

### Nonpolar

37

## Wether or not a polyatomic molecule will be polar or nonpolar (if it contains polar bonds) depends completely upon...?

### The molecular geometry of the molecule

38

## Polar molecules mix ___ with other polar molecules but mix ____ with nonpolar molecules

###
Well

Badly

39

## Define valance bond theory

### An advanced model of chemical bonding in which electrons reside in quantum-mechanical orbitals localized on individual atoms that are a hybridized blend of standard atomic orbitals; chemical bonds result from an overlap of these orbitals

40

## The energy of interaction is usually _____ (or _____) when the interacting atomic orbitals contain a total of two electrons that can spin pair

###
Negative

Stabilizing

41

## In valance bonding theory, what do the atoms in a molecule reside in?

###
Quantum-mechanical atomic orbitals

(Such as s,p,d,f and hybrid combinations of these)

42

## In valence bond theory, Which two ways can a covalent bond occur?

###
When two half-filled orbitals with spin pairing of the two valence electrons

Or less commonly, the overlap of a completely filled orbital with an empty orbital

43

##
In valance bond theory, what determines the shape of the molecule?

### The geometry of the overlapping orbitals

44

## Define hybridization

### A mathematical procedure in which standard atomic orbitals are combined to form new, hybrid orbitals

45

## Define hybrid atomic orbitals (hybrid orbitals)

### Orbitals formed from the combination of standard atomic orbitals that correspond more closely to the actual distribution of electrons in chemically bonded atom

46

## Are hybrid orbitals still located on individual atoms? What is the difference between orbitals and hybrid orbitals

###
Yes

Hybrid orbitals are different shapes and energies than standard atomic orbitals

47

## Hybrid orbitals _____ the energy of the molecule by _____ the orbital overlap in a bond

###
Minimize

Maximizing

48

## What does the standard number of atomic orbitals added together always equal?

###
The number of hybrid orbitals formed

(ie total number of orbitals is conserved)

49

## What does the particular combination of standard atomic orbitals added together determine?

### The shape and energy of the hybrid orbitals formed

50

## Tendency to hybridize _____ with the number of bonds formed

### Increases

51

## What does the hybridization of one s orbital and three p orbitals result in?

### Four sp3 hybrid

52

## What does the hybridization if one s and two p orbitals result in?

### Three sp2 hybrids and one leftover UN hybridized p orbitals

53

## What does the hybridization of one s and one p orbital result in?

### Two sp orbitals and two left over unhybridized p orbitals

54

## Define Pi bond

### The bond that forms between two p orbitals that overlap side to side

55

## Which bond is stronger sigma or Pi?

### Sigma

56

## Why do Pi bonds make rotation impossible?

### you have to break the bond to rotate

57

## define sigma bond

### The resulting bond that forms between a combination of any two s,p or hybridized orbitals that overlap end to end

58

## in general sigma bonds are ____ than pi bonds

### stronger

59

## what is the hybridization of linear geometry?

### sp ( + 2 unhbridized p)

60

## what is the hybridization of trigonal planar?

### sp2 ( + 1 unhbridized p)

61