Solving a problem in chemistry section 10 point 56

56. A thermal decomposition of the salt in the presence of catalyst B and the salt formed in the gas that supports combustion. The interaction of the salt with hydrochloric acid A distinguished yellow-green gas G and B. The gases produced salt and D do not interact. By contacting the salt with a solution B of silver nitrate white precipitate. Name unknown substances, write equations of all the reactions mentioned.