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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: hkalfighter on April 17, 2006, 12:57:52 PM

Title: can ether form H-bonds with water
Post by: hkalfighter on April 17, 2006, 12:57:52 PM

ether is used to extract organic layer in solvent extraction because it's immiscible with water . However , can ether form H-bond with water with it's O on ROR coz there are 2 lone pair e- ? if it can , why is it immiscible with water ?

Title: Re: can ether form H-bonds with water
Post by: Albert on April 17, 2006, 01:15:12 PM

No, they don't. You can foresee it looking at their boiling points.

Title: Re: can ether form H-bonds with water
Post by: hkalfighter on April 17, 2006, 01:48:19 PM

why don't they form ? they have an O with lone pair e- which should attract the bared H on H2O
How about aldehyde and ketone , there are H-bonds with H2O . what s the difference between ether and aldehyde , ketone ?

Title: Re: can ether form H-bonds with water
Post by: Albert on April 17, 2006, 03:13:31 PM

Ethers can be only H-bond acceptor. In fact, small ethers, such as dimethyl ether, are soluble in water. For what concerns the others, their oxygen atoms are less accessible for hydrogen bonding to water molecules: that's why ethers are unsoluble in water.

Title: Re: can ether form H-bonds with water
Post by: Donaldson Tan on April 17, 2006, 03:23:14 PM

the key word is accessibility

Title: Re: can ether form H-bonds with water
Post by: hkalfighter on April 17, 2006, 03:38:56 PM

accessibility ?? does it mean bared H can't get access to the O on ether due to the steric hinderance of large alkyl group attached to it ?

Title: Re: can ether form H-bonds with water
Post by: Albert on April 17, 2006, 04:07:19 PM

Yes, indeed.

Title: Re: can ether form H-bonds with water
Post by: hkalfighter on April 18, 2006, 02:38:54 AM

how about aldehyde and ketone ?
they don't form H-bond with each other but with H2O , am i right ?
and how about RF , i thought there's H-bond with H2O too , am i right ?

Title: Re: can ether form H-bonds with water
Post by: hkalfighter on April 18, 2006, 08:23:03 AM

why does Aldehyde or ketone form H-bond with water or i have made it wrong ?

Title: Re: can ether form H-bonds with water
Post by: AWK on April 19, 2006, 02:01:19 AM

Ethyl ether is slightly soluble in water. There is no doubt that these molecules form hydrogen bonds.
I searched CSD database and found at least 4 examples with HB water-ethyl ether with distance of 265 to 300 pm between donor and acceptor.

Title: Re: can ether form H-bonds with water
Post by: Mitch on April 19, 2006, 02:17:24 AM

Okay sounds good to me. :)