Given that the internal energy change is -20KJ the change in enthalpy is : -17 KJ
Given data :
P1 = 7 kPa
P2 = 4 kPa
V1 = 3 m³
V2 = 6 m³
Applying the relationship below
Change in enthalpy = change in internal energy + ( P2V2 - P1V1 )
= -20 + ( 4*6 - 7*3 )
= -20 + ( 24 - 21 )
= - 17 KJ
Hence we can conclude that the change in enthalpy is : -17 KJ
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