Answer:
453 kJ
Step-by-step explanation:
A gas mixture is contained in a cylinder and piston assembly.
The gas mixture released 903 kJ in form of heat into its surroundings, that is, q = - 903 kJ.
The internal energy during this process decreased by 450 kJ, that is, ΔU = -450 kJ.
We know that,
ΔU = q + w
w = ΔU - q = -450 kJ - (- 903 kJ) = 453 kJ
The gas is compressed, that is, work is done by the surroundings on the gas, and the work involved is 453 kJ.