Okay, so once and for all - ethers, ketones, H-bonding.

This forum made possible through the generous support of SDN members, donors, and sponsors. Thank you.

pfaction

Full Member
10+ Year Member
Joined
Mar 14, 2010
Messages
2,225
Reaction score
79
They can accept hydrogen bonds, but cannot make them, that I understand. So are we to assume that in any protic solution, the ethers and ketones will have 0 hydrogen bonds.

Members don't see this ad.
 
do we have a more thorough explanation of why this is so?

According to what MedPR has said about the AAMC FL answers, that would be correct. (though your statement would be absolutely technically correct only if the solution were aprotic)

but if the solution is aprotic, there are no Hbonds to be had.
 
do we have a more thorough explanation of why this is so?



but if the solution is aprotic, there are no Hbonds to be had.
Right, which would make OP's statement saying they would form 0 H-bonds totally correct. In protic solution they will still hydrogen bond to some extent, but this is technical and the AAMC ignores it.
 
Members don't see this ad :)
So will an short alkane with only ethers, ketones and/or aldehyde be water soluble?

If the short alkane has an only ester group will be it water soluble?
 
So will an short alkane with only ethers, ketones and/or aldehyde be water soluble?

If the short alkane has an only ester group will be it water soluble?

AAMC 9 has a question like this where they say that an ether cannot hydrogen bond w/ water

but in their answer they refer to h-bonding as the donation of H's to water by the ether

weirrddd

i'd like some clarification on this as well.
 
Hydrogen bonding is not a necessary property for a substance to be soluble in water. Polarity is sufficient.

Ethers can hydrogen bond with water, but because it's not a reciprocal form of hydrogen bonding, the AAMC doesn't recognize it.
 
Soo...in response to these question in MCAT AAMC land

1. So will a short alkane with one ethers, ketones and/or aldehyde be water soluble?

2.)If the short alkane has an only ester group will be it water soluble?

1.) No
2.) Yes
 
I thought you saying:

"Ethers can hydrogen bond with water, but because it's not a reciprocal form of hydrogen bonding, the AAMC doesn't recognize it. "

means that ethers are not soluble in water! Please, purely speak as if you're the AAMC, b/c this thread is confusing the s*** out of me...haha
 
I thought you saying:

"Ethers can hydrogen bond with water, but because it's not a reciprocal form of hydrogen bonding, the AAMC doesn't recognize it. "

means that ethers are not soluble in water! Please, purely speak as if you're the AAMC, b/c this thread is confusing the s*** out of me...haha
I simply meant the AAMC doesn't recognize hydrogen bonding in that case. Why should a polar compound need to hydrogen bond to be soluble in water?
 
Ethers and ketones are hydrogen bond acceptors, but not hydrogen bond donors. Ethers and ketones will hydrogen bond with protic solvents, but not with each other.

gettheleadout is quoting me properly, however the question I was referring to was a pretty simple question to answer provided you knew that the other 3 answers (other than H-bond) were completely wrong. The question/answer basically said this: "Alcohols have a higher boiling point than ethers because they hydrogen bond in aqueous solution." H-bonding is pretty high yield and (in my opinion) is simple enough to understand rather than try to memorize a list of rules.
 
Top