Dear Student, When solutions of barium chloride and sodium sulphate are mixed together, then an insoluble precipitate of barium sulphate and solution of sodium chloride is obtained. This reaction is a precipitation reaction. The chemical equation for reaction between barium chloride and sodium sulphate is represented as follows BaCl2 (aq) + Na2SO4 (aq) → BaSO4 (↓) + 2NaCl (aq) Also note that the above reaction is a double displacement reaction since the two compounds exchange their respective ions which results in the formation of two new compounds. The above reaction will not take place if both the reactants are present in solid state. Regards