Chemistry help involving enthalpy and such?

[bryon_barker]

I have a series of questions that I don't know how to do. You don't have to solve for the answer if you don't want to, just help me as far as equations and steps I would go through to answer these questions please:

a.Calculate the work done(in Joules)when 57.3 g of tin dissolves in excess acid at 1.09atm and 21degrees celcius. Assume ideal gas behavior.
Sn(s)+2H+(aq) -> Sn²+(aq) + H2(g)

b.Hydrogen sulfide, H2S, is a foul-smelling gas, which burns to form sulfur dioxide.
2H2S(g)+3O2(g)->2SO2(g)+2H2)(g) ?H= -1036kJ/mol
Calculate the enthalpy change in kJ when 20.0 g of hydrogen sulfide is burned.

c.How much heat is released when 9.7g of CS2 and 9.7g of Cl2 are mixed and react according to the following equation? CS2(g)+3Cl2(g)->S2Cl2(g)+CCl4(g) ?H= -230 kJ/mol

d.Determine the amount of heat(in kJ)given off when 8.25x10^4g of ammonia are produced according to the equation below.
N2(g)+3H2(g)->2NH3(g) ?H(reaction)= -92.6kJ/mol

I hope you guys understand the equations.