Answer:
Q = 30.90 kJ, W = 12.36 kJ, ΔE = 18.54 kJ.
Explanation:
The expansion is happening at constant pressure without a phase change, thus, the heat can be calculated by:
Q = n*c*ΔT
Where n is the number of moles, c is the molar heat capacity, and ΔT is the temperature variation (final - initial), thus:
Q = 39.1*20.8*(38.0 - 0.0)
Q = 30904.64 J
Q = 30.90 kJ
The work done by a expansion at constant pressure is:
W = P*ΔV
Where P is the pressure (1 atm = 101325 Pa), and ΔV the volume variation (final - initial). Vfinal = 998 L = 0.998m³, Vinitial = 876 L = 0.876 m³.
W = 101325*(0.998 - 0.876)
W = 12361.65 J
W = 12.36 kJ
By the first law of the thermodynamics, the variation of the internal energy ΔE is:
ΔE = Q - W
ΔE = 30.90 - 12.36
ΔE = 18.54 kJ
