Long Test 3

Question 1

this theory describes covalent bonds as the overlap of half-filled atomic orbitals (each containing a single electron) that yield a pair of electrons shared between two bonded atoms

Answer 1

Valence bond theory

Question 2

When can we say that orbitals on different atoms overlap?

Answer 2

When a portion of one orbital and a portion of a second orbital occupy the same region of space

Question 3

According to the valence bond theory, a covalent bond results when
(A.) an orbital on one atom overlaps an orbital on a second atom
(B.) the single electrons in each orbital combine to form an electron pair
(C.) A & B

Answer 3

C.

Question 4

What serves as the physical link between the two atoms through covalent bonds?

Answer 4

The mutual attraction between the negatively charged electron pair and the two atoms’ positively charged nuclei

Question 5

TRUE OR FALSE: Orbitals that overlap less are stronger than those that overlap extensively

Answer 5

False

Question 6

When two atoms approach each other, what happens to the sum of their energies?

Answer 6

It changes

Question 7

TRUE OR FALSE: When the atoms are far from each other there is no overlap meaning that the sum of their energies equates to zero

Answer 7

True

Question 8

When the _____ are slightly stronger than the repulsions, the _____ of the system decreases

Answer 8

attractions, energy

Question 9

TRUE OR FALSE: The energy of the system is at its most stable when it is at its lowest

Answer 9

True

Question 10

The optimum distance between the two bonded nuclei

Answer 10

bond distance

Question 11

If the distance between the nuclei were to decrease and the repulsion forces were to become stronger than the attractive forces (in closer proximity to each other), what would happen to the energy of the system? Does the system stabilize or destabilize?

Answer 11

The energy of the system would increase, meaning that it would destabilize

Question 12

Other than the distance between the two orbitals what else affects their overlapping?

Answer 12

The orientation of the orbitals

Question 13

TRUE OR FALSE: The overlap of two p orbitals is at its greatest when the orbitals overlap sideways

Answer 13

False: it is at its greatest when they overlap head-to-head

Question 14

What kind of bonds do two s orbitals, one s + one p orbital, and two p orbitals form?

Answer 14

sigma bonds (σ bonds)

Question 15

In sigma bonds, where is the electron density concentrated?

Answer 15

In the region along the internuclear axis; a line between the nuclei would pass through the center of the overlap region

Question 16

A type of covalent bond that results from the side-by-side overlap of two p orbitals

Answer 16

pi bond (π bond)

Question 17

In pi bonds, where do the regions of orbital overlap lie?

Answer 17

On opposite sides of the internuclear axis

Question 18

Sigma bonds are represented as what kind of bonds in Lewis structures?

Answer 18

single bonds

Question 18

What is a node?

Answer 18

A plane with no probability of finding an electron that is found along the internuclear axis

Question 19

Double bonds consist of?
(A.) one pi bond, one sigma bond
(B.) two pi bonds
(C.) two sigma bonds

Answer 19

A.

Question 20

Triple bonds consist of?
(A.) one pi bond, two sigma bonds
(B.) one sigma bond, two pi bonds

Answer 20

B.

Question 21

TRUE OR FALSE: There can only be one pi bond in any one location

Answer 21

False: sigma bond

Question 22

The wave function ψ, contains information about?

Answer 22

Each orbital and the wavelike properties of electrons in an isolated atom

Question 23

What is the process of combining the wave functions for atomic orbitals called?

Answer 23

Hybridization

Question 24

Hybridization is mathematically accomplished by what combination of atomic orbitals?

Answer 24

Linear combination (LCAO)

Question 25

What are the new orbitals that result from hybridization called?

Answer 25

Hybrid orbitals

Question 26

If the electron configuration of oxygen is 1s2, 2s2, and 2p4, what are the valence orbitals? (A.) four 2p orbitals (B.) four 2p orbitals and one 2s orbital (C.) three 2p orbitals and one 2s orbital (D.) two 2p orbitals

Answer 26

C.

Question 27

TRUE OR FALSE: Hybrid orbitals only exist in isolated atoms

Answer 27

False, they do not exist in isolated atoms. They are formed only in covalently bonded atoms.

Question 28

TRUE OR FALSE: The type of hybrid orbitals formed in a bonded atom depends on its electron-pair geometry as predicted by the VSEPR theory

Answer 28

True

Question 29

TRUE OR FALSE: Hybrid orbitals overlap to form sigma bonds, while unhybridized orbitals overlap to form pi bonds

Answer 29

True

Question 30

Sp - ? Sp2 - ? Sp3 - ?

Answer 30

Sp - 2 pi bonds Sp2 = 1 pi bond Sp3 = no pi bond

Question 31

TRUE OR FALSE: The longest bond is the triple bond

Answer 31

False, it is the single bond

Question 32

one s orbital + one p orbital = ?

Answer 32

one sp hybrid orbital

Question 33

one s orbital + two p orbitals = ?

Answer 33

3 sp2 hybrid orbitals

Question 34

one s orbital + three p orbitals = ?

Answer 34

4 sp3 hybrid orbitals

Question 35

What kind of hybrid orbital contains one lobe that is significantly larger than the other?

Answer 35

sp hybrid orbitals

Question 36

TRUE OR FALSE: The number of hybrid orbitals formed are always greater than the number of atomic orbitals that are combined

Answer 36

False: The number of hybrid orbitals formed always equals the number of atomic orbitals that are combined

Question 37

TRUE OR FALSE: The set of sp orbitals appears similar in shape to the original p orbital

Answer 37

True

Question 38

The sp set is two equivalent orbitals that point ___ degrees from each other (A.) 90 (B.) 125 (C.) 45 (D.) 180

Answer 38

D.

Question 39

TRUE OR FALSE: The pi bond is harder to break than the sigma bond

Answer 39

False, the sigma bond is harder to break

Question 40

TRUE OR FALSE: Before hybridization, you have two different orbitals with two different energies but after hybridization, you now have two orbitals with the same energy

Answer 40

True

Question 41

Any central atom surrounded by just two regions of valence electron density in a molecule will exhibit what kind of hybridization?

Answer 41

sp hybridization

Question 42

The valence orbitals of a central atom surrounded by three regions of electron density consist of a set of?

Answer 42

three sp2 hybrid orbitals and one unhybridized p orbital

Question 43

An atom surrounded by a tetrahedral arrangement of bonding pairs and lone pairs consists of (A.) four sp3 hybrid orbitals (B.) one sp2 hybrid orbital and three sp3 hybrid orbitals (C.) one sp hybrid orbital, two sp2 hybrid orbitals, and one sp3 hybrid orbital

Answer 43

A.

Question 44

TRUE OR FALSE: Sp3 orbitals cannot hold lone pairs

Answer 44

False, it can

Question 45

TRUE OR FALSE: bonding pairs occupy more space than lone pairs

Answer 45

False

Question 46

TRUE OR FALSE: Lone pairs have bond angles slightly distorted from the ideal

Answer 46

True

Question 47

Tetrahedrals have angles of?

Answer 47

109.5 degrees

Question 48

Linear electron geometries have angles of?

Answer 48

180 degrees

Question 49

Trigonal planars have angles of?

Answer 49

120 degrees

Question 50

Trigonal bipyramids have angles of?

Answer 50

90 degrees, 120 degrees, and 180 degrees

Question 51

Octahedrals have angles of?

Answer 51

90 degrees

Question 52

To describe the five bonding orbitals in a trigonal bipyramidal arrangement, we must use five of the valence shell atomic orbitals which are?

Answer 52

the s orbital, the three p orbitals, and one of the d orbitals

Question 53

This occurs when a central atom is surrounded by five regions of electron density

Answer 53

sp3d hybrid orbitals

Question 54

With an octahedral arrangement of six hybrid orbitals, we must use which six valence shell atomic orbitals in order to give us sp3d2 hybrid orbitals?

Answer 54

one s orbital, three p orbitals, and two of the d orbitals in its valence shell

Question 55

TRUE OR FALSE: sp3d and sp3d2 hybridizations are only possible for atoms that have d orbitals in their valence subshells

Answer 55

True

Question 56

If there are 2 regions of electron density, what is its arrangement, hybridization, and angle?

Answer 56

linear, sp, 180 degrees

Question 57

If there are 3 regions of electron density, what is its arrangement, hybridization, and angle?

Answer 57

trigonal planar, sp2, 120 degrees

Question 58

If there are 4 regions of electron density, what is its arrangement, hybridization, and angle?

Answer 58

tetrahedral, sp3, 109.5 degrees

Question 59

If there are 5 regions of electron density, what is its arrangement, hybridization, and angle?

Answer 59

trigonal bipyramidal, sp3d, 90 degrees on top, 120 degrees on the bottom

Question 60

If there are 6 regions of electron density, what is its arrangement, hybridization, and angle?

Answer 60

octahedral, sp3d2, 90 degrees, 90 degrees top and bottom

Question 61

VSEPR theory - predicts the shapes of molecules Hybrid orbital theory - ?

Answer 61

Provides an explanation for how those shapes are formed

Question 62

TRUE OR FALSE: VSEPR theory was devised to rationalize experimentally observed molecular geometries

Answer 62

False, Hybridization

Question 63

TRUE OR FALSE: Hybridization theory works well for larger central atoms wherein the valence-shell electron pairs are farther from the nucleus, meaning that there are fewer repulsions

Answer 63

False, it works better for molecules containing small central atoms wherein the valence electron pairs are close together in space

Question 64

Bonds that are formed by the direct overlap of two hybrid orbitals (s or p orbitals)

Answer 64

Single bonds

Question 65

TRUE OR FALSE: The additional electrons shared in a multi-bond are not a result of directly overlapping hybrid orbitals but are a result of side-by-side overlap of two regular "p" atomic orbitals

Answer 65

True, these are called pi bonds

Question 66

Single bond - ? Double bond - 1 sigma bond, 1 pi bond Triple bond - ?

Answer 66

Single bond - 1 sigma bond Triple bond - 1 sigma bond, 2 pi bonds

Question 67

TRUE OR FALSE: rotation around single bonds (sigma bonds) occurs easily because the end-to-end orbital overlap does not depend on the relative orientation of the orbitals one each atom in the bond

Answer 67

True

Question 68

TRUE OR FALSE: Hybridization involves sigma bonds, pi bonds, lone pairs of electrons, and single unpaired electrons (radicals)

Answer 68

False, hybridization does not include pi bonds

Question 69

Resonance forms occur when various arrangements of ? are possible (A.) hybrid orbitals (B.) molecules (C.) pi bonds (D.) sigma bonds

Answer 69

C.

Question 70

TRUE OR FALSE: Since the arrangement of π bonds involves only the hybridized orbitals, resonance does not influence the assignment of hybridization.

Answer 70

False, it only involves unhybridized orbitals

Question 71

the attraction to a magnetic field that arises in molecules that have unpaired electrons

Answer 71

paramagnetism

Question 72

What is magnetic susceptibility?

Answer 72

it measures the force experienced by a substance in a magnetic field

Question 73

Materials in which all of the electrons are paired are called what?

Answer 73

diamagnetic

Question 74

TRUE OR FALSE: diamagnetic materials weakly repel a magnetic field

Answer 74

True

Question 75

TRUE OR FALSE: Paramagnetic materials are permanent magnets, while diamagnetic materials are not

Answer 75

False, they both don't act as permanent magnets (only in the presence of an applied magnetic field)

Question 76

What theory provides an explanation of chemical bonding that accounts for the paramagnetism of the oxygen molecule?

Answer 76

Molecular orbital theory

Question 77

TRUE OR FALSE: The molecular orbital theory also accounts for molecules that violate the octet rule and more molecules with more complicated bonding that can't be described with Lewis structures

Answer 77

True

Question 78

If valence bond theory uses hybrid orbitals, what does the molecular orbital theory use?

Answer 78

The combination of atomic orbitals to yield molecular orbitals that are delocalized over the entire molecule rather than being localized on its constituent atoms

Question 79

Who developed methods to describe molecular orbitals?

Answer 79

Walter Kohn

Question 80

Sigma and sigma-star molecular orbitals are formed by the combination of?

Answer 80

two s atomic orbitals

Question 81

In molecular orbitals, what does the plus sign indicate?

Answer 81

locations of the nuclei

Question 82

Combining wave functions of two p atomic orbitals along the internuclear axis creates?

Answer 82

two molecular orbitals: sigma p and sigma star

Question 83

TRUE OR FALSE: when in-phase waves combine, constructive interference produces a wave with less or no amplitude

Answer 83

False, it produces a wave with greater amplitude

Question 84

When ? waves combine, destructive interference produces a wave with less or no amplitude

Answer 84

out-of-phase waves

Question 85

If combining the wave functions of two p orbitals along the internuclear axis creats two molecular orbitals sigma p and sigma star p, what does the side-by-side overlap of each two p orbitals result in?

Answer 85

two pi molecular orbitals: pi star p and pi p (wherein one contains the axis and the other contains the perpendicular)

Question 86

Is the internuclear axis horizontal or vertical?

Answer 86

horizontal

Question 87

Molecular orbitals are so closely spaced that they are described as?

Answer 87

bands

Question 88

Which is higher and lower in energy between the valence band and the conduction band?

Answer 88

higher - conduction band lower - valence band

Question 89

What is a diamagnetic substance?

Answer 89

It is a substance that is repelled by an induced magnetic field

Question 90

TRUE OR FALSE: Solutions have previously been defined as homogeneous mixtures, which means that the composition of the mixture is different throughout

Answer 90

False, it is UNIFORM/SAME

Question 91

What is the relative amount of a given solution component called?

Answer 91

concentration

Question 92

The medium in which the other components are dispersed or dissolved

Answer 92

solvent

Question 93

What is a solution in which water is the solvent called?

Answer 93

aqueous solution

Question 94

A component of a solution that is typically present at a much lower concentration than the solvent

Answer 94

Solute

Question 95

dilute - ? ? - of relatively high concentration

Answer 95

dilute - of relatively low concentration concentrated - pf relatively high concentration

Question 96

It is defined as the number of moles of solute in exactly 1 liter (1L) of the solution

Answer 96

Molarity

Question 97

The process whereby the concentration of a solution is lessened by the addition of solvent

Answer 97

Dilution

Question 98

What are the substances undergoing reaction called?

Answer 98

reactants

Question 99

What are the substances generated by the reaction called?

Answer 99

products

Question 100

A reaction in which dissolved substances react to form one or more insoluble solid products

Answer 100

precipitation reaction

Question 101

The extent to which a substance may be dissolved in water, or any solvent

Answer 101

solubility

Question 102

TRUE OR FALSE: A substance will precipitate when solution conditions are such that its concentration exceeds its solubility

Answer 102

True

Question 103

TRUE OR FALSE: Acid-base reactions are the same as redox reactions

Answer 103

False, acid-base reactions involve a transfer of protons in hydrogen atoms and are known to be exothermic, while redox reactions involve a change in oxidation number for one or more reactant elements