[vichid]

so the problem is:

Consider a mixture of air and gasoline vapor in a cylinder with a piston. The original volume is 70. cm3. If the combustion of this mixture releases 1151. J of energy, to what volume will the gases expand against a constant pressure of 680. torr if all the energy of combustion is converted into work to push back the piston?

Could anyone solve it for me please? I think you would use the equation w = -P(delta V) but im still not sure.

Help is appreciated 

[english]

I only see one unknown.  Go from there.