Topscore Ochem Question

[FutureDental88]

---

Members do not see this ad.

For this problem B looks nonpolar too due to cancellation. How can I tell the difference.

Correct answer is D.




http://imageshack.us/photo/my-images/4/ochem.jpg/



Uploaded with ImageShack.us

 

[mh0000]

B will hydrogen bond to one another, and will not be very soluble.

 

[ugination87]

B will hydrogen bond to one another, and will not be very soluble.

what he said

 

[FutureDental88]

I dont get it...

 

[mh0000]

While B is not very polar (it probably has a slight polarity because of the lone pair of electrons on the nitrogen), the p-diaminebenzenes will hydrogen bond to each other. It cannot hydrogen bond to the solvent as it has no N-H or O-H bonds. Same reason why water is not soluble in organic solvents. In fact, every answer choice except D has the capability to hydrogen bond.

 

[AlbinoPolarBear]

Hydrogen bonding = soluble in water, but not soluble in oils (eg pentane).
Little hydrogen bonding = not soluble in water, but soluble in oils (eg pentane).

Ether groups are bad at hydrogen bonding.
Amine and carboxylic acid groups are good at hydrogen bonding.

It's in pentane, so pick one that's bad in hydrogen bonding.

Therefore.. molecule with ether groups, D.

 

[FutureDental88]

got it ! Thanks alot !