Question

Calculate the change in internal energy when a closed system releases 380 kJ of heat and has 275 kJ of work done on it by the surroundings.

(a) 105 kJ
(b) -105 kJ
(c) 655 kJ
(d) -655 kJ

Answer 1

The change in internal energy of a system can be calculated by subtracting the work done on the system from the heat transferred to the system. In this case, the change in internal energy is -105 kJ.

Step-by-step explanation:

The change in internal energy of a system can be calculated using the equation: ΔU = Q - W, where ΔU is the change in internal energy, Q is the heat transferred to the system, and W is the work done on the system.

In this case, the system releases 380 kJ of heat (Q = -380 kJ) and has 275 kJ of work done on it (W = -275 kJ). Substituting these values into the equation, we get: ΔU = -380 kJ - (-275 kJ) = -105 kJ.

Therefore, the change in internal energy of the system is -105 kJ.