Volumetric Analysis Help!!!

Many transition ometals occur naturally as sulfides. The follwing procedure was used to determine the sulfur conten of a particular metallic sulfide.
0.800g or metallic sulfur was heated un a stream of oxygen until reaction was complete and the sulfur dioxide produced, after colling, was absorbed in excess aqueous hydgroen peroxide ti firn sykfyruc acud, 25.0mL of 0.2000molL^-1 sodium hydroxidde solution was required for complete netraulisation of sulfuric acid,


The number of moles of sulfuric acid formed from the sulfur dioxide,

The mass (in g) in this sulfuric acid,

The percentage (by mass) of sulfur in the metallic sulfide.


understand part b, c just need help figuring how to start the equation for a. cannot start b c as this is a multistep process