8. Thermochemistry

Which of the following exchanges of energy has a positive sign for heat (relative to the system)?

If a cylinder equipped with a piston expands against an external pressure of 1.25 atm, increasing the volume of a cylinder by 0.500 L and releasing 25.0 J of heat, what is ΔE for the process?

A 0.1250-g sample of octane (C₈H₁₈) is burned in a bomb calorimeter with a heat capacity of 5.1 × 10² J/℃. The temperature inside the calorimeter increases by 11.8℃. What is the ΔE (in kJ/mol octane) for the combustion of octane?