A student has 10 mL of a solution that might contain any or all of the following cations at 0.01 M concentrations: Mn2+, Ba2+, Ag+ , and Cu2+. Addition of 10 mL of 1 M HCl causes a precipitate to form. After the precipitate is filtered off, 1 M H2SO4 is added to the filtrate and another precipitate forms. What is the second precipitate