How do we know if something dissolves

[ddsnp]

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Hey guys I was wondering if someone can help me out expalining how we know an acid or a base can dissolve in a ether solution. Why does aniline and benzoic acid dissolve in the ether solution. Does everything dissolve in an ether solution?

Thanks

 

[DATMan30]

Hey guys I was wondering if someone can help me out expalining how we know an acid or a base can dissolve in a ether solution. Why does aniline and benzoic acid dissolve in the ether solution. Does everything dissolve in an ether solution?

Thanks

Remember from general chem that "like dissolves like". Basically a polar solution will dissolve in a polar solution and a non-polar solution will dissolve in a non-polar solution, for the most part. Hope this helps 😀

 

[ddsnp]

but then why can aniline and benzoic acid come out of an ether layer?

 

[DICK]

know your solubility rules

 

[ddsnp]

god for some reason i thought an ether wasn't polar...my bad..i think this clears things up. Does this mean hexane will not dissolve in a ether layer because an ether is polar??


Thanks for all your help

 

[cowsgomoo]

god for some reason i thought an ether wasn't polar...my bad..i think this clears things up. Does this mean hexane will not dissolve in a ether layer because an ether is polar??


Thanks for all your help

I thought ether was non-polar. Aniline and benzoic acid come out of ether because they are polar in aqueous base and acid solutions. I thought this was correct. I might be wrong.

 

[ddsnp]

I thought ether was non-polar. Aniline and benzoic acid come out of ether because they are polar in aqueous base and acid solutions. I thought this was correct. I might be wrong.

I'm all confused now because I'm lookin in the kaplan white book and they just say that benzoic acid is insoluble in water. What is the difference between dissolve and soluble because I might be getting tthat mixed up. I think you are right cowsgomoo. Is aniline and benzoic acid non polar because of its large benzene ring?

 

[DICK]

I'm all confused now because I'm lookin in the kaplan white book and they just say that benzoic acid is insoluble in water. What is the difference between dissolve and soluble because I might be getting tthat mixed up. If someone can clear this up it would be greatly appreciated.

Ha, the difference between disolve and soluble...

Disolve: To cause to pass into solution: dissolve salt in water.

Soluble: That can be dissolved, especially easily dissolved: soluble fats.

 

[cowsgomoo]

I'm all confused now because I'm lookin in the kaplan white book and they just say that benzoic acid is insoluble in water. What is the difference between dissolve and soluble because I might be getting tthat mixed up. I think you are right cowsgomoo. Is aniline and benzoic acid non polar because of its large benzene ring?

Are you by chance talking about separation of organic compounds? If so aniline can be extracted form either by an acid where the amino group will pick up an H+ and become polar. For benzoic acid it will be deprotonated by a base and become polar and come out of the ether solution. The aqueous solution will now contain aniline of benzoic acid.
Hope this helps if not let me know. I hope I am correctly understanding your question.

 

[ddsnp]

Are you by chance talking about separation of organic compounds? If so aniline can be extracted form either by an acid where the amino group will pick up an H+ and become polar. For benzoic acid it will be deprotonated by a base and become polar and come out of the ether solution. The aqueous solution will now contain aniline of benzoic acid.
Hope this helps if not let me know. I hope I am correctly understanding your question.

Yes thats exactly what I'm talking about. But, I'm getting confused on if those two can be soluble in ether. Do you know what i'm talking about? I understand what you just said, but doesn't ether have to be soluble or not soluble so the aniline and benzoic acid can mix with it initially? May sound confusing, sorry.

 

[DrTacoElf]

Yes thats exactly what I'm talking about. But, I'm getting confused on if those two can be soluble in ether. Do you know what i'm talking about? I understand what you just said, but doesn't ether have to be soluble or not soluble so the aniline and benzoic acid can mix with it initially? May sound confusing, sorry.

In organic extractions you have 2 distinct phases. Organic (ether usually) and aqueous. Essentailly you have a compound thats mixed with other stuff in one of your phases in the beginning. You coarse one of these compounds into another phase by acidifying it (protonation) or the reverse. Then you remove the phase you do not desire and repeat. Eventually you will get your desired compound in either the organic or aqueous phase. Then its just a matter of evaporation or recrystalization to recover what you want.

Remember like dissolves like so NON POLAR means it will be in an organic phase by default.