well a normal acid requires H2O and can be measured using the pH scale
so for instance
-->
H2O H+ + OH-
<----
you then add say Na+ which removes the OH- shifts the equlibrium to the foward reaction and leaves an excess of H+ ions, you have your acid
but lewis acid is based on the principle that an acid is an electron pair donator or acceptor
so you have say a reaction like this
-->
NH4 NH3- + H+
<----
where adding say Na+ will remove the ammonia ions to leave an excess of H+ ions, and there you also have an acid
the only problem is NH3- + H+ are in solution
and since my project is to create an acid independent of water i need to find out if i can extract the lewis acid from solution once it's ready..?
Note that the pH scale doesn't apply to a lewis acid.
however i intend to create a theoretical pH scale for my lewis acid during my project.