KNO₂ potassium nitrite is a salt that is very soluble in water. Its dissolution forms the species K ⁺ and NO^2-. Potassium sulphate (K2SO4) is a salt that is very soluble in water. dissolution forms the species K ⁺ and SO₄ ^2-

1) Write the balance equations of the dissolution of KNO₂ and K₂SO₄ 2) Which mass of KNO₂ should be weighed to prepare a solution S₁ of 100 mL or the concentration K ⁺ = 0,1 mol / L ? 3) Which mass of K₂SO₄ should be weighed to prepare a S₂ solution of 250 mL or the concentration K ⁺ = 0.2 mol / L ? 4) What is the mass concentration of KNO₂ in S₁ ?