[joe955]

I'm trying to understand gassing. When gassing a liquid base to make the liquid base a salt what does the gas do to the liquid base that turns it to salt and what determines which gas to use when gassing a liquid base?

[joe955]

This question must have an unknown answer.

[Borek]

Your questions are so convoluted it is almost impossible to understand what you are asking about.

[joe955]

Yes I'm learning through the crash course method so my talk is probably not correct to a trained chemist but the idea that I'm looking for is that after a reduction is made the new molecular structure is present and most of the processes that I'm reading conclude with saying "now that you have completed the reduction all thats left is to gas it". But no explaination on why gasing is needed or even what type of gas to use.
Why is gasing needed?
What type of gas is used? (is there a formula or basic knowledge to figuring out what type of gas is needed?)
I'm hoping maybe if I knew what the gasing step is for, then I might understand what gas would be used.

[sjb]

OK, coupling posts 1 and 4 one possible interpretation is that you have, for instance, reduced a nitro-containing compound, say nitrostyrene down to benzylamine.

Benzylamine is a liquid, and a base.

If you then "gas" this by bubbling hydrogen chloride gas through the mixture for considerable time then the HCl will react with the amine to form the ammonium salt, which is solid.

But without details of the actual procedure you're following this is very hand wavy.

S

[Borek]

In this case you are converting amine to its ionic salt. Ionic salts are usually soluble in water, but insoluble in polar solvents.

[joe955]

OK that seems to help clear things.
And just for a reference, the reduced nitro-containing compound benzylamine is called benzylamine when it is in a liquid form. Now when the HCL reacts with the amine to form the ammonium salt, which is solid, is it still called benzylamine?

[Borek]

No, it is benzylamine hydrochlroide.

[joe955]

When a compound's name has HCL attached to it, the HCL identifies that the compound is in the form of a salt instead of in liquid form?

[Borek]

No, it just means that H⁺ protonates nitrogen making molecule positively charged, thus ion.