State the symbol equation for the conversion of sulfur dioxide to sulfur trioxide in the Contact process, 2SO2(g) + O2(g) ⇌ 2SO3(g)

Describe tests to identify the anions: (a) carbonate, CO3^2-, by reaction with dilute acid and then testing for carbon dioxide gas (b) chloride, Cl^-, bromide, Br^-, and iodide, I^-, by acidifying with dilute nitric acid then adding aqueous silver nitrate (c) nitrate, NO3^-, by reduction with aluminium foil and aqueous sodium hydroxide and then testing for ammonia gas (d) sulfate, SO4^2-, by acidifying with dilute nitric acid then adding aqueous barium nitrate (e) sulfite, SO3^2-, by reaction with acidified aqueous potassium manganate(VII)