What is the chemical formula of the major species' that exists when it is added to water for HI, AgCl, HNO2?

Question

I just don't know what "major species' that exists" mean. Can some one explain to me and do an example for me. Thanks

Answer 1

Your question plus my useless answer=

U.q+M.u.A=2pts

Answer 2

By "major species," it means, "what form are most of the atoms present in."

HI is an ionic compound consisting of H+ and I- ions.  It is present as molecules in the gas phase, but when added to water, the ions dissociate (this is true of all strong acids).  So the major species present in solution will be H+ (which is sometimes said to react with water to form H3O+ or other complexes with water, so put this if you want) and I-.

AgCl is also an ionic compound, but unlike HI, it is insoluble in water.  Thus, the major species present will just be solid AgCl.

HNO2 is again an ionic compound, consisting of an H+ ion and an NO2- ion.  However, unlike HI this acid is not a strong acid, so it will not dissociate to a large degree in water.  Thus, the major species will be aqueous HNO2