2011 DAT Destroyer #106 OCHEM

[pandalove89]

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Which compound will dissolve in concentrated HBr or HCl but not in water?

a) octanal
b) 2-octanone
c) 2-octanamine
d) 1,2 - diethylbenzene
e) 2- octanol

I thought it as d) because benzene isn't soluble in water but the answer is c). Why? 😡

 

[hplfe]

because amines longer than 3 carbons long aren't water soluble. I guess its just one of those things that you have to memorize

 

[Dew517]

So in these types of problems, just follow one rule: Acids dissolve bases, and bases dissolve acids.

The only base that is in the list is C. The strong acid will protonate the amino group and will bring it into the aqueous layer thereby dissolving it

D is not base and will not be dissolved in acid. Also C is definitely insoluble in water because of the 8 carbon chain.

 

[pandalove89]

So in these types of problems, just follow one rule: Acids dissolve bases, and bases dissolve acids.

The only base that is in the list is C. The strong acid will protonate the amino group and will bring it into the aqueous layer thereby dissolving it

D is not base and will not be dissolved in acid. Also C is definitely insoluble in water because of the 8 carbon chain.

Isn't that a bit counter intuitive? I thought aldehydes and ketones were acidic..?

 

[pandalove89]

bump

 

[pandalove89]

Isn't that a bit counter intuitive? I thought aldehydes and ketones were acidic..?

any more suggestions?