A solution of sodium salt of unknown anion when treated with Magnesium chloride solution gives white precipitate only on boiling. The anion is

A solution of sodium salt of unknown anion when treated with Magnesium

1.	A solution of sodium salt of unknown anion when treated with Magnesium chloride solution gives white precipitate only on boiling. The anion is
Answer» `SO_(4)^(2-)` `HCO_(3)^(-)` `CO_(3)^(2-)` `NO_(3)^(-)`. Solution :BICARBONATES on heating form insoluble carbonates `MgCl_(2) + 2NaHCO_(3)rarr2NaCl+Mg (HCO_(3))_(2)` `Mg(HCO_(3))_(2)overset(Delta)rarrMgCO_(3)darr+CO_(2)+H_(2)O`