Answer:
a) Change in internal energy of the system = - 135.2 J
b) Change in internal energy of the environment = 135.2 J
Step-by-step explanation:
From the mathematical statement of the first law of thermodynamics,
ΔU = Q - W
ΔU = Change in internal energy of the system = ?
Q = heat transferred into or out of the system. For this system, heat is transferred into it, Q = 77.8 J
W = workdone = 213 J (positive because work is done by the system on the environment)
ΔU = 77.8 - 213 = - 135.2 J
The change in internal energy of the environment is just the negative of that of the system. The balance is always so.
Hence, change in internal energy of the environment = -(- 135.2) = 135.2 J