[Billqaz3]

Hey guys I'm really confused about choosing solvents for organic acid base reactions. In my book it gives the example

Propyne    + Sodium amide  Sodium propynide + Ammonia
acid             base                           conjugate base        conjugate acid
pka=25        pkb=-22                      pkb=-11                 pKa=36 

The book says the correct solvent to use here would be liquid ammonia which has a pka of 36 and would accommodate bases with pkb > -22.

My confusion stems from the fact that in the book it mentions that if the acid and base added to solution was stronger then the protonated or depotonated version of the solvent. (So if the pKa or pKb is lower then the solvent's pka and pkb). The acid wouldn't survive in the solution and would instead react with the solvent. So for the reaction given above the sodium amide would dissolve in the solvent but not react with the solvent. But the propyne acid which has a pka of 25 which is lower then the ammonia's 36 would react with ammonia. I thought the point was to find a solvent that wouldn't react with either of the reactants. Am I mistaken? Is the acid always supposed to react with the solvent? What are the rules for figuring out which reactant should react with the solvent?
 
Thanks in advance.