Quiz 1

Question 1

Why do most elements want to reach a full octet?

Answer 1

So they can be stable, anything less can be reactive

Question 2

How many bonds does H O N C form respectivley?

Answer 2

1 2 3 4

Question 3

formal charge =

Answer 3

of valence e- (number of nonbonding e + 1/2 number of bonding e)

Question 4

electronegativity

Answer 4

an atoms ability to attract electrons

increases across and up the periodic table (towards fluorine)

Question 5

what forms dipole moments?

Answer 5

the partial charges formed when atoms shared electrons in polar covalent bonds

Question 6

Rules of bond line structure

Answer 6

1. all corners or end points in the lines are a carbon
2. H are not drawn, its is assumed that all C have enough H to be stable
3. triple bonds are drawn linearly not in the zig zag formation

Question 7

What is the strongest intermolecular force?

Answer 7

hydrogen forces

Question 8

What does a hydrogen need to be bonded to to have hydrogen intermolecular forces?

Answer 8

N O F

Question 9

Name three intermolecular forces

Answer 9

1. hydrogen forces
2. dipole dipole interactions
3. dispersion forces

Question 10

How can branching affect bp solubility, state of matter, density, etc?

Answer 10

it changes the surface area
no branching= larger surface area
branching = smaller surface area

Question 11

the — is the reason for bonding

Answer 11

electron

Question 12

Constructive interference

Answer 12

creates bonding MO, lower E than antibonding MO

Question 13

Destructive interference

Answer 13

creates a higher E antibonding MO + a node

bc the waves do not have effective overlap

Question 14

MO theory

True or false? If you start with 8 orbitals before hybridization you will end with 4 after hybridization?

Answer 14

false, orbitals are conserved in MO theory

Question 15

HOMO

Answer 15

highest (energy) occupied molecular orbital

Question 16

LUMO

Answer 16

lowest (energy) unoccupied molecular orbital

Question 17

sp3 hybridization

Answer 17

The averaging of one 2s orbital with three 2p orbitals to explain tetrahedral geometry
- creates 4 sp3 orbitals, 0 p orbitals unaffected
- single bonds
- 109.5 bond angles

Question 18

sp2 hybridization

Answer 18

the averaging of 1 2s orbital with 2 2p orbitals to explain trig. planar geometry
- 3 sp2 orbitals, 1 p orbital unhybridized
- 1 pi bond 1 sigma bond
- 120 bond angles

Question 19

Sp hybridization

Answer 19

the averaging of 1 2s orbital with 1 p orbital to explain linear geometry
- 2 sp orbitals, 2 p orbital unhybridized
- 2 pi bonds 1 sigma bond
- 180 bond angles

Question 20

sigma bond

Answer 20

formed by the overlap of hybridized orbitals

all single bonds are sigma bonds

Question 21

pi bonds

Answer 21

formed by the side to side overlap of unhybridized p orbitals

double and triple bonds

Question 22

Functional group

Answer 22

a group of atoms that reacts the same way each time, because they are predictable they are used as classifications

Question 24

describe an alkane

Answer 24

a single bond structure

Question 25

describe an alkene

Answer 25

a double bond structure

Question 26

describe an alkyne

Answer 26

a triple bond structure

Question 27

describe an amine

Answer 27

N + H and another group/molecule

Question 28

describe a ketone

Answer 28

double bonded oxygen onto a c-c chain

Question 29

describe an alcohol

Answer 29

OH

Question 30

describe a thiol

Answer 30

like an alcohol but with S instead of O

Question 31

describe an alkyl halide

Answer 31

single bond with a halogen on the other end

Question 32

If an O has a = charge how many bonds and lone pairs does it have?

Answer 32

two bonds, two lone pairs

Question 33

if an O has a - charge how many bonds and lone pairs does it have?

Answer 33

one bond, three lone pairs

Question 34

An O has three bonds and one lone pair, what is its charge?

Answer 34

positive

Question 35

If a N has a = charge how many bonds and lone pairs does it have?

Answer 35

three bonds, one lone pair

Question 36

If a nitrogen has two bonds and two lone pairs what is its charge?

Answer 36

negative

Question 37

If a nitrogen has a + charge how many bonds/ lone pairs does it have?

Answer 37

four bonds, zero lone pairs

Question 38

Carbocation

Answer 38

a carbon with three bonds and no lone pairs, sp2 | MAD UNSTABLE

Question 39

Carboanion

Answer 39

a carbon with three bonds and one lone pair, sp3

Question 40

Resonance

Answer 40

Used to represent the distribution of e- through a molecules pi orbitals | important for stability

Question 41

e- that participate in resonance, aka are unhybridized

Answer 41

delocalized electrons

Question 42

e- that do not participate in resonance, aka are hybridized/attatched to atom

Answer 42

localized electrons

Question 43

If an atom has a lone pair and a pi bond will the lone pair likely be localized or delocalized

Answer 43

likely localized bc only one or the other can participate in resonance

Question 44

Name the three rules of resonance structures

Answer 44

1. NEVER push towards an sp3 atom, they are roadblocks 2. NEVER expand an octet, the atoms can have less but not more 3. NEVER break a single bond

Question 45

Allylic positions

Answer 45

positions that are adjacent, not attatched to the pi bond

Question 46

Name the five patterns of resonance

Answer 46

1. allylic lone pairs 2. allyic positive charge 3. lone pairs adjacent to a positive charge 4. a pi bond between atoms of differing electron negativity 5. conjugated pi bonds in a ring

Question 47

Name the three rules of determining the significance of a resonance structure

Answer 47

1. The most significant model will be one that has all filled octets (aka a neutral molecule) 2. The most significant contributor will be one that has the fewest formal charges 3. The most significant contributor will be one that has a charge on the more electronegative atom