Question

Comparing hexane and octane, which is a stronger london dispersion force and why

Answer 1

octane does because it has a larger surface area

Answer 2

what about benzil and benzophenone?

Answer 3

would it be benzil for the same reason?

Answer 4

if were talking bout london dispersion forces, then yes. but i'm not sure how their dipole would play out in terms of cancelling out. I think benzophenone would be more polar and thus have greater attraction to one another due to these partial positive/negative charges

Answer 5

i thought both of them were non-polar molecules

Answer 6

they are, but benzil has Oxygens in somewhat different orientations while benzophenone has only one oxygen and it's dipole is concentrated in one direction. remember that dipoles have directional magnitude

Answer 7

for the dipole-dipole forces i just said that the two of them dont't have any because they are both non-polar.

Answer 8

london dispersion forces are present in all molecules right?

Answer 9

sorry i thought you said they're polar, they ARE polar. unequally distributed sharing of electrons in the carbonyl group

Answer 10

yep, london dispersion forces are always there

Answer 11

okay, and how about 2-napthol and naphthalene - i said that 2-nepthol has the greatest dispersion force since the molecules are pratically identical, only 2-nepthol has an extra O

Answer 12

and you said that benzil and benzophenone are polar? i thought they were non-polar

Answer 13

you're right about 2 nephtol, but it is because it is an alcohol and thus it is capable of hydrogen bonding (which is a polar characteristic)

Answer 14

im asking a million questions at once haha im sorry,

Answer 15

i didnt think there was h bonding in 2-napthol

Answer 16

hydroxide counts as a hydrogen bond?

Answer 17

there is, anytime you have an alcohol you have hydrogen bonding

when you have H attached directly to O, N or F you are capable of H-bonding

Answer 18

yes

Answer 19

haha it's okay, I'm glad i can help someone who's into chem

Answer 20

so the presence of the OH is what also makes the london dispersion force stronger?

Answer 21

by the way benzil>benzophenone is terms of polarity

Answer 22

does this make it more polar?

Answer 23

and haha i really do enjoy chemistry : )

Answer 24

well, what you mean presence of OH, you mean in solution?

Answer 25

haha thats good, it gets really really complex

Answer 26

there is an OH attached to a C in 2-napthol that isn't in naphthalene

Answer 27

yep thats a hydroxide, which makes 2-naphtol an alcohol, hence the suffix -ol

Answer 28

and both are polar, correct?

Answer 29

yep, both are polar. if you have elements highly electronegative, typically, you;ll have a polar molecule

Answer 30

how do i tell which one has the dtronger dipole-dipole force?

Answer 31

thats something you have to calculate by finding their dipole moment. but you can usually eye it out based on the number of the electronegative atoms and their angles

Answer 32

okay because their surface areas look about the same

Answer 33

oh wait, that's for dispersion forces.

Answer 34

not sure how to tell which has the stronger dipole-dipole or dispersion force since they're so similiar

Answer 35

does the presence of OH make 2-napthol have a stronger dispersion force?

Answer 36

they're kinda similar but not really.. if you have to compare 2 molecules and one has a dipole and the other has no dipole (non-polar), automatically, the one with the dipole has greater intermolecular forces

Answer 37

but both have dipole-dipole forces and i need to state which is stronger and why

Answer 38

say because on has a greater dipole moment..