A Problem on Salt Analysis!

A colourless salt \((A)\),soluble in water,gives a mixture of three gases \((B),(C),(D)\) along with water vapours.\((C)\) is not oxidisable. \((B)\) turns red litmus blue,\((C)\) turns blue litmus red and gas\((D)\) is neutral towards litmus paper. Gas \((B)\) is also obtained when \((A)\) is heated with \(\ce{NaOH}\) and gives brown ppt with \(\ce{{K}_{2}Hg{I}_{4}}\). Solution thus obtained gives white ppt \((E)\) with \(\ce{Ca{Cl}_{2}}\) solution in presence of \(\ce{C{H}_{3}COOH }\). \((E)\) decolourises \(\ce{{Mn{O}_{4}}^{-}/{H}^{+}}\). Gas \((C)\) turns lime water milky while gas \((D)\) burns with blue flame and is fatal when inhaled. Find the molecular mass of salt \((A)\).

Two more problems on Salt Analysis are as follows:

1. A Problem on Salt Analysis! 2

2. A Problem on Salt Analysis! 3