Can someone help me with this?

4.25g sample of solid ammonium nitrate dissolves in 60.0g of water in a coffee-cup calorimeter, the temperature drops from 22.0 c to 16.9 c. assume that the specific heat of the solution is the same as that of pure water. calculate delta(h) (in kj/mol nh4no3) for the solution proces.

Balance the following reaction. as2s3 + 9o2 → 2as2o3 + so2

Afuel has 30.43% nitrogen and 69.57% oxygen. find the molecular formula of the compound if it has a mass of 92 grams per mole a.no b.n2o4 c.no2 d.n4o8