How much work is done when 2.0 liters of CH4(g) undergoes combustion in excess oxygen at 0 degrees Celsius and 1.00 bar (assuming the volume of water formed is negligible)?

Answer 1

CH4 + O2 --> CO2 + 2H2O

Calculate volume of CH4 at the conditions.
Calculate volume of CO2 at the conditions listed (although I wonder how CH4 will burn with a T of zero C).
Then w = -pdV = -p(vfinal-Vinitial)
I assume you want work in J; using bar won't get that. I would convert 1 bar to atmosphere(about 0.9869 atm) and the answer comes out with work in L*atm. Convert to J by multiplying by 101.325.