Firstly, I don't think that HCl + H2O will produce Hydrogen
Peroxide. Cl2 is Chlorine gas, which is found at group VII of the
periodic table.
I still believe that the product is Hydrochloric acid.
As for why is the solution acidic, the correct answer I supposed.
is because of the presence of Hydrogen ion.
The front statement "...to form an acidic solution..." acts as a
smokescreen, but it's actually testing you on the knowledge of what
gives acids it's property.
For this case, it's because of the Hydrogen ions.
