How do I use Hess’ direct method to solve this?

How many liters of measured at 17 C and 756 torr, must be burned to liberate 2.80*10^4 kj of heat?

2C2H6 (g) + 7O2 (g) = 4CO2(g) + 6h2O(l)

deltaH=-3.12*10^3 kj