Chemistry - Salt Analysis Question with Solution | TestHub

When MnSO₄ is heated with K₂CO₃ and KNO₃, the manganese is oxidized to potassium manganate (K₂MnO₄). This compound is green. The reaction involves the oxidation of Mn(II) to Mn(VI) in the presence of an oxidizing agent (KNO₃) and a basic flux (K₂CO₃).

The balanced chemical equation for the reaction is:

$$2{\mathrm{MnSO}}_4+4{\mathrm{K}}_2{\mathrm{CO}}_3+{\mathrm{KNO}}_3\to 2{\mathrm{K}}_2{\mathrm{MnO}}_4+{\mathrm{KNO}}_2+2{\mathrm{K}}_2{\mathrm{SO}}_4+4{\mathrm{CO}}_2$$

The green color observed in the residue is due to the formation of potassium manganate (K₂MnO₄).