Question

The HCl in a 0.10 M HCl solution is 100% dissociated. What are the molar concentrations of HCl, H3O+, and Cl- in the solution ?

Answer 1

The first statement means that `HCl` fully dissociates in solution, since it is a strong acid,

`HCl + H_2O rightleftharpoons H_3O^(+) + Cl^-`

The hydrochloric acid will protonate one equivalent of water molecules, and the chloride ion will dissociate in the same way.

Hence,

`[H_3O^+]_ "eq" = [Cl^-]_"eq" approx 0.10 "M"`, and

`[HCl]_"eq" = 0.00 "M"`