Chemistry- Intermolecular forces

Hi guys need help urgently, i'm so s*** at chemistry

Explain the difference in the boiling temperatures between the 2 isomers- ethanol which boils at 78 degrees C and methoxymethane which boils at -25 degrees C

Thanks guys would really appreciate the help! and not the help of ignorant b******'s as below :smile:

(edited 13 years ago)

Reply 1

gozatron

Original post by Anonymous 16

Hi guys need help urgently, i'm so s*** at chemistry

Which types of intermolecular forces hold together the molecules in:
a) hydrogen bromide
b) propane
c) methanol

Explain the difference in the boiling temperatures between the 2 isomers- ethanol which boils at 78 degrees C and methoxymethane which boils at -25 degrees C

Thanks guys would really appreciate the help!

I won't answer your homework for you but i'll try to point you in the right direction, otherwise how would you learn?

For your first question think about the different atoms that exist in each of the molecules, some of them have some high electronegative differences, some of them have lone pairs of electrons, some has neither. Try drawing out the structures of each molecule and then think about all different intermolecular bondings and why do they occur.

For your second question, what conditions makes intermolecular bonding maximised?

Reply 2

Charzhino

^ same as above, look at the differences in the structures

Reply 3

Anonymous 16

hey guys i solved the first part, which i now deleted
but really brain-dead on that question, i don't get chemistry at all and will be leaving once this AS is over

(edited 13 years ago)

Reply 4

Charzhino

Original post by Anonymous 16

hey guys i solved the first part, which i know deleted
but really brain-dead on that question, i don't get chemistry at all and will be leaving once this AS is over

i know deleted? what are you brain-dead on , the second part?

Reply 5

Anonymous 16

Original post by Charzhino

i know deleted? what are you brain-dead on , the second part?

theres no need for the sarcasm

Reply 6

Sammydemon

Original post by Anonymous 16

They are both very different functional groups. The ethanol is an alcohol where as the methoxymethane is an ether. Some brief reading on their properties should tell you why the ether is more volatile.

Reply 7

Charzhino

Original post by Anonymous 16

theres no need for the sarcasm

im not being sarcastic lol, you didnt word your sentences properly I was confused on what you meant. So I take it your stuck on the second part. Well what does methoxyether have that ethanol doesnt? What functional group.

Reply 8

Anonymous 16

Original post by Charzhino

misunderstanding lol, methoxymethane has ethers f.group, whereas ethanol has an alcohols f.group...i don't know what else :s-smilie:

oh ethers does not have hydrogen?

(edited 13 years ago)

Reply 9

Charzhino

Original post by Anonymous 16

misunderstanding lol, methoxymethane has ethers f.group, whereas ethanol has an alcohols f.group...i don't know what else :s-smilie:

oh ethers does not have hydrogen?

yes, ethanol has OH which means it can hydrogen bond to other ethanols which is a very strong type of intermolecular force. The ether has no OH groups therefore cannot Hydrogen bond which means it isnt as strong and has a weaker boiling point.

Reply 10

Sammydemon

Original post by Anonymous 16

misunderstanding lol, methoxymethane has ethers f.group, whereas ethanol has an alcohols f.group...i don't know what else :s-smilie:

oh ethers does not have hydrogen?

I think you will understand better if you just read your text book/the internet on these two functional groups. The ether is much more volatile than the alcohol i.e. the molecules aren't bothered about hanging around close to each other. The reason should be easy for you to find.