Answer: Heat transfer (Q) is 521 kJ.
Explanation: In the piston-cilinder assembly, we can suppose that the oxygen act as an ideal gas, so, it can be used the General Gas Equation:
PV=RT, where:
P is pressure;
V is volume;
m is mass;
M is molar mass;
R is a constant: R = 8.314. m³bar.K⁻¹.mol⁻¹;
T is temperature;
Using this equation, find the intial temperature:
PV = RT
1.2 = .8.314.
.T
T = 1.924. K
To determine the final temperature, use Combined Gas Law:
=
, in which, the left side of the equality is related to the initial values and the right side, to the final values.
As pressure is constant:
T =
T =
T = 3.85. K
With the temperatures, calculate the heat transfer of the process:
Q = m.k.ΔT, where:
k is heat constant
ΔT = T -
Q = m.k.ΔT
Q = 2.1.35.(3.85 - 1.92).
Q = 521 kJ
The heat transfer in the process is 521 kJ.