Such as substance is called an acid
Yes - it is a "Lewis salt" formed from a Lewis acid and a Lewis base. Most chemists would not call it a salt which is a term they would reserve for the product of the neutralisation of an H+ acid. They would call this an adduct or a complex.
Since HCl is a strong acid, you can assume 100% deprotonation. Thus you will have 0.5M H[+].
Buffers
Hydrogen ion (H+) [technically it is hydronium ion (H3O+)] that determines the strength of an acid. A mole of hydrochloric acid (HCl) produces 1 mole of H+ ions, then that is a strong acid. Weak acids give smaller amounts of H+ for a mole of substance.
A lewis acid is a lone pair acceptor, the H+ ion has no electrons, so can easily accept a lone pair from another atom.
No it is not a Lewis Acid, H+ is!
accoring to lewis concept it is base H^+(lewis acid) + H^2O(lewis base)---->(H^3O)^+
HX ---> H+ + X- Keq = [H+][X-]/[HX]
weak acid
H+ or a proton.
acid in solution.
Acids release H+ in an aqueous solution.
an acid donates the h plus ion and alkali does the opposite
Well, it depends on what ion you are talking about: the H+ ion, 'proton,' or the H- hydride ion. Anions, Lewis bases accept the proton or H+ ion (HCl); but active metals can react with H- to form metal hydrides (NaH for example)
Carbonic acid(H2CO3/H(CO3)2
I think you mean H+ + HCO3- --> H2CO3