JEE Advanced 2020 Full Test 4 Paper 1

Salt(A) produces golden yellow flame on flame test. Aqueous solution of (A) produces a white precipitate with barium chloride solution. The precipitate is insoluble in dilute mineral acids. On thermal decomposition in presence of SiO2,(A) forms a salt (B) and gas(C). When treated with an acid(D), salt (B) forms NaCl,SiO2 and H2O. What is the molar mass of (D)?