Answer:
Final Energy is 75.9 kJ
Explanation:
Given:
Heat absorbed, Q = 21.6 kJ
Work done by the system on the surrounding, W = - 6.9 kJ
Initial internal energy of the system, Ei = 61.2 kJ
From the first law of thermodynamics, we have
Change in energy = Heat absorbed + Work done
or
Final energy (Ef) - Initial energy (Ei) = Q + W
on substituting the values in the above formula, we get
Ef - 61.2 kJ = 21.6 kJ + (- 6.9 kJ)
or
Ef = 14.7 kJ + 61.2 kJ
or
Ef = 75.9 kJ
Hence, the final Energy is 75.9 kJ