The pH of a 0.046 M HC2H3O2 solution is 3.04. Why don't the two equimolar solutions of HCl and HC2H3O2 have the same pH?
1) The concentration of HCl is different from the concentration of HC2H3O2
2) HCl is a strong acid while HC2H3O2 is a weak acid
3) The dissociation constant of HCl is different from the dissociation constant of HC2H3O2
4) The pH scale is not linear