Post-lab #3-3: Suppose you have a solution that might contain any or all of the following cations: Cu2+, Ag+, Ba2+, Mn2+. The addition of HBr cause a precipitate to form. After the precipitate is separated by filtration, H2SO4 is added to the supernatant liquid, and another precipitate forms. This precipitate is separated by filtration, and a solution of NaOH is added to the supernatant liquid until it is strongly alkaline. No precipitate is formed. Which cations are not present in the original solution? Choose all applied.