Answer:
The ion present in the sample solution is Mn2+
Step-by-step explanation:
(a) No precipitate formed when an aqueous solution of NaCl was added to the sample solution.
Most chlorides are quite soluble in water except for he H g 2 C l 2, that is an insoluble salt. Since no precipitation formed upon addition of NaCl, H g 2 + was not present in the sample.
(b) No precipitate formed when an aqueous solution of Na2SO4 was added to the sample solution.
The B a S O 4 is an insoluble salt too. Since no precipitation formed upon addition of N a 2 S O 4 , the ion B a 2 + was not present in the sample.
(c) A precipitate formed when the sample solution was made basic with NaOH.
As the M n ( O H ) 2 is insoluble in this last solution, the precipitate formed corresponds to B a S O 4 and H g 2 C l 2 compounds , therefore it can be concluded that the present ion in the sample solution is Mn+2.