[Karakth]

The question was as follows:

Explain why a number of salts are produced when ammonia is reacted with chloromethane.

The only salt I know occurs is N(CH₃)₄⁺ Cl^-

That is, unless HCl counts as a salt...And last I remember it doesn't.

So what other salts can you get? NH₄Cl when an unreacted NH₃ molecule meets a Cl^- ion?

[lemonoman]

When I first looked at this, I say to myself, "A salt formed by reaction of ammonia with methyl chloride...seems odd to me."  Only because CH₃Cl isn't an ionic compound, and it won't readily dissociate intil ions...I was thinking

CH₃Cl --not--> CH₃⁺ + Cl^-

Which definitely isn't right.

So, in aqueous solution, I dare say that ammonia and methyl chloride would not form salts.


On another note, perhaps a direct reaction occurs between the NH₃ and CH₃Cl...

NH3 + CH3Cl --> (NH3)CH3Cl --> CH3NH2 + HCl        [Not much I would guess...but a tiny tiny bit]
then the HCl + NH3 --> NH4Cl

And the NH4Cl, as you mentioned, is actually a salt as we had discussed.

Anybody else wanna take a stab?

[Yggdrasil]

Ammonia, because of nitrogen's lone pair, is a nucleophilic species.  Methyl chloride has an electrophilic carbon.  The two will react in a substitution reaction to produce CH₃NH₂.  Since a byproduct of the reaction is HCl, this can be protonated to form CH₃NH₃⁺.  However, since methyl groups are electron-donating, methylating the nitrogen will only increase its nucleophilicity, so the resulting primary amine will react with additional methyl chloride molecules to form the secondary amine, then the tertiary amine, and finally, the quatenary amine, N(CH₃)₄⁺.  Therefore, the primary salt will be N(CH₃)₄Cl, with minor amounts of the primary, seconday, and tertiary ammonium chlorides.

[lemonoman]

Whoa...that's heavy stuff.  Even though I didn't ask the question, I fell enlightened,,,