A gas absorbs 200 J of heat and expands against the external pressure of 1.5 atm from a volume of 0.5 Lt to 1.0 Lt, Calculate the change in internal energy.
a) 120.025 J b) 115.05 J c) 135.025 J d) 124.025 J
Dear Student,
The internal energy can be calculated using equation:
E = q +W
E = q + PΔV
Given q = 200J
P = 1.5 atm
V2 = 1 L
V1= 0.5 L
W= - P(V2-V1) since work is done by the system the sign will be -ve
W = -1.5(1- 0.5) = -0.75 L atm
W = -0.75 X 101.35 J = -75.98 J
(1L atm = 101.35 J)
E = 200 J - 75.98 J = 124.025 J
So, correct option d) 124.025 J
Regards