Answer
Because no precipitates formed upon addition of NaCl or Na2SO4, we can conclude that Hg22+ and Ba2+ are not present in the sample because Hg2Cl2 and BaSO4 are insoluble salts. However, Mn2+ may be present since Mn2+ does not form a precipitate with either NaCl or Na2SO4. A precipitate formed with NaOH; the solution must contain Mn2+ because it forms a precipitate with OH− [Mn(OH)2(s)].
Work Step by Step
Because no precipitates formed upon addition of NaCl or Na2SO4, we can conclude that Hg22+ and Ba2+ are not present in the sample because Hg2Cl2 and BaSO4 are insoluble salts. However, Mn2+ may be present since Mn2+ does not form a precipitate with either NaCl or Na2SO4. A precipitate formed with NaOH; the solution must contain Mn2+ because it forms a precipitate with OH− [Mn(OH)2(s)].
