Answer:
(a) W = 1329.5 J = 1.33 KJ
(b) ΔU = 24.27 KJ
Explanation:
(a)
Work done by the gas can be found by the following formula:
[tex]W = P\Delta V[/tex]
where,
W = Work = ?
P = constant pressure = (0.991 atm)([tex]\frac{101325\ Pa}{1\ atm}[/tex]) = 100413 Pa
ΔV = Change in Volume = 18.7 L - 5.46 L = (13.24 L)([tex]\frac{0.001\ m^3}{1\ L}[/tex]) = 0.01324 m³
Therefore,
W = (100413 Pa)(0.01324 m³)
W = 1329.5 J = 1.33 KJ
(b)
Using the first law of thermodynamics:
ΔU = ΔQ - W (negative W for the work done by the system)
where,
ΔU = change in internal energy of the gas = ?
ΔQ = heat added to the system = 25.6 KJ
Therefore,
ΔU = 25.6 KJ - 1.33 KJ
ΔU = 24.27 KJ
