[ChapMuthu]

Question: The compound P has C,H,O and N as elements. A white pp+ was formed when P was acidified. Identify a structural feature of P which caused this precipitation.

I was thinking on the lines of: maybe its an ammonium salt of long chain carboxylic acid [e.g.- (CH)5COO-(NH4)+]. When a strong dilute acid is added, the carboxylic acid will be formed and since its a long chain molecule, it will precipitate out of the solution?

Am I right or is it some other obvious compound?

Thanks for answering.

[zeshkani_usa]

did you do a melting point test?

[fledarmus]

What is it precipitating out of?

If you have a non-polar solvent, then you have probably gone from a neutral compound to a charged compound - consider possible basic functional groups.

If it is water, then you have probably gone from a charged compound to a neutral compound - consider possible organic salts. Actually, there aren't many types of organic salts with only C, H, O, and N as elements - I can only think of ammonium salts of carboxylic acids.

If it is a polar solvent that is not water, then it is hard to predict even the type of compound without more information.

[ChapMuthu]

Melting point test is not given. Water is the solvent. That's what I thought as well, it should be an ammonium salt.