[Chemistry] questions on solubilty of bases and naphthalen-2-ol

[xechox_06]

Homework Statement

2-hydroxybenzenediazonium ion is allowed to react with naphthalen-2-ol to form 1-(4-hydroxyphenylazo)-2-naphthol

Homework Equations

1.Why is amine having a different solubility in water and dilute hydrochloric acid?

2.Why is naphthalen-2-ol dissolves in sodium hydroxide instead of water or acidic aqueous solvent?

3.Does naphthalen-2-ol react with aliphatics amines and how to use it to distinguish between aliphatics and aromatic amines?

The Attempt at a Solution

1.I guess it is because when it dissolve in dilute hydrochloric acid, the H+ ions react with the OH- ions from the amine, so the equilibrium shift towards the right, and therefore amine dissolves better in dilute hydrochloric acid?

2.Is it related to basify...but I even don't know what is basify. Or it is because naphthalen-2-ol is too bulky to dissolve in water?

3.My guess is no. But I also don't know why...

Really thanks a lot for you guys help

 

[chemisttree]

1. What happens to an amine in acidic solution? It has nothing to do with the alcohol (-OH) functionality...

2. Think of naphthalene-2-ol as an enol. What would a base do in that case?

3. To answer this question you need to understand the mechanism of the reaction. Remember that the diazonium salt is added slowly to a solution that contains an excess of NaOH, so the reaction occurs under basic conditions. Diazonium ion is an electrophile in this reaction.