An ideal gaseous reaction (which is a hypothetical gaseous reaction that conforms to the laws governing gas behavior) occurs at a constant pressure of 30.0 atm and releases 74.4 kj of heat. before the reaction, the volume of the system was 7.20 l. after the reaction, the volume of the system was 2.00 l. calculate the total internal energy change, δe, in kilojoules. express your answer with the appropriate units.

The total change in internal energy would simply be calculated using the formula:

ΔU = - P (V2 - V1) + ΔH

where ΔU is the change in internal energy; P is constant pressure = 30 atm = 3,039,750 Pa; V2 is final volume = 2 L = 0.002 m^3; V1 is initial volume = 7.20 L = 0.0072 m^3; while ΔH is the heat = - 74,400 J (heat released so negative)

Therefore:

ΔU = - 3,039,750 Pa * (0.002 m^3 - 0.0072 m^3) + ( - 74,400 J)

ΔU = - 58,593.3 J = - 58.6 kJ