Chapter 3: Bonding and Chemical Interactions

Question 1

When you have two or more atoms with similar electronegativities interacting, how do the electrons interact to form an ion?

Answer 1

Complete transfer of electrons

Question 2

Which is greater…energy required to form covalent bond or energy released upon formation of ionic bond?

Answer 2

Energy required to form ions through covalent bonding

energetically unfavorable to create ions

Question 3

What are the intermolecular interactions like between covalent compounds?

Answer 3

Discrete molecular units with relatively weak intermolecular interactions resulting in lower melting and boiler points and poor conductivity

Question 4

What is bond order? Explain the three common ones.

Answer 4

the number of shared electron pairs between two atoms

Single bond = bond order of 1
Double bond = bond order of 2
Triple bond = bond order of 3

Question 5

What three factors characterize a covalent bond?

Answer 5

bond length, bond energy, and polarity

Question 6

What is bond length?

Answer 6

Average distance between two nuclei of atoms in a bond

Question 7

How does the number of shared electron pairs affect the bond length?

Answer 7

As the number of shared electron pairs increases, the two atoms are pulled closer together resulting in a decreased bond length

Question 8

Which of the bonds is shortest? Longest?

[Single, double, triple]

Answer 8

Longest: Triple
Middle: Double
Shortest: Single

Question 9

What is bond energy?

Answer 9

The energy required to break a bond by separating its components into their isolated atomic states

Question 10

How does the number of shared electron pairs affect the bond energy?

Answer 10

The greater the number of pairs of electrons shared between the atomic nuclei, the more energy is required to break the bonds holding the atoms together

Question 11

What is polarity?

Answer 11

When two atoms have a relative difference in electronegativity

Question 12

How does electronegativity effect electron density in covalent bonds?

Answer 12

The atom with the higher electronegativity gets the larger share of the electron density

Question 13

Which end of the dipole is the less electronegative atom? More electronegative atom? (positive vs negative)

Answer 13

Less electronegative atom is the positive end

More electronegative atom is the negative end

Question 14

How are electrons shared between two molecules with nearly identical electronegativities?

Answer 14

There is an equal distribution of electrons

Question 15

What is a nonpolar covalent bond?

Answer 15

No separation of charge across the bond due to differences in electronegativity

Question 16

Which bonds can exhibit a purely equal distribution of electrons?

Answer 16

Only bonds between atoms of the same element therefore they have the same electronegativities

Question 17

What is a polar covalent bond?

Answer 17

Atoms that differ moderately in their electronegativities that share electrons unevenly

Question 18

What must be the difference in electronegativity to be considered a covalent bond?

Answer 18

Between 0.5 and 1.7

Question 19

What must be the difference in electronegativity to be considered a polar covalent bond? Nonpolar?

Answer 19

Between 0.5 and 1.7 for polar

Between 0 and 0.5 for nonpolar

Question 20

How and what is the distribution of charge for polar covalent bonds?

Answer 20

The more electronegative element acquires a great portion of the electron density becoming a partial negative (δ− ) and the less electronegative electron acquires a smaller portion of the electron density taking on a partial positive charge (δ+)

Question 21

What is dipole moment and what are the units?

Answer 21

Measure of the polar bond or molecule as a vector quantity and is measured in Debye units (C*m)

Question 22

What is a coordinate covalent bond?

Answer 22

Both of the shared electrons originated on the same atom (a long pair from one atom attacked another atom)

Question 23

What is a coordinate covalent bond?

Answer 23

Both of the shared electrons originated on the same atom (a long pair from one atom attacked another atom’s unhybridized p orbital)

Question 24

What is a Lewis acid? a Lewis base?

Answer 24

Lewis acid is any compound that will accept a lone pair of electrons
Lewis base is any compound that will donate a pair of electrons to form a covalent bond?

[nucleophile/electrophile]

Question 25

What type of “bond” are Lewis acids and bases found in?

Answer 25

Coordinate covalent bond

Question 26

Which shell are bonding electrons found in for covalent bonds?

Answer 26

They are found in the valence shell

Question 27

What is formal charge and how do you find it?

Answer 27

The hypothetical charge that would result if all bonding electrons are shared equally across a covalent bond

(#VE it should have) - (#VE in bonded atom in respect to equal sharing of electons)

Question 28

What is oxidation state and how do you find it?

Answer 28

The hypothetical charge that would result if all bonding electrons are assigned to the more elctronegative atom in the bond

(#VE it should have) - (#VE in bonded atom in respect to elecronegativity)

Question 29

What is oxidation state and how do you find it?

Answer 29

The hypothetical charge that would result if all bonding electrons are assigned to the more elctronegative atom in the bond

(#VE it should have) - (#VE in bonded atom in respect to elecronegativity)

Question 30

What is it called if you can draw Lewis structures for a particular compound that differ only in the arrangement of the electron pairs?

Answer 30

Resonance

Question 31

How do you determine which arrangement may be most likely if there are several resonance forms?

Answer 31

The arrangement that minimizes the formal charge and magnitude of formal charge is usually most stable

Question 32

In respect to resonance structures, what is the actual arrangement of the electrons in the compound?

Answer 32

It would be a hybrid of all the possible resonance structures

Question 33

Which elements have an exception to the octet rule?

Answer 33

all elements in and beyond the third period because they take on more than eight electrons in their valence shells being placed into the d subshell