Thermodynamic Work Formula
It is the quantity of energy transferred from one system to another. It is a generalization of the concept of mechanical work in mechanics. It can be related to a variety of physical systems, in the case of an ideal gas is:
Work = (number of moles) * (ideal gas constant) * (change of temperature)
The equation is:
W= n R ΔT
Where:
W: Thermodynamic work
R: Ideal gas constant. (8.314 kg*m2/s2*mol*K)
ΔT: Absolute Temperature in Kelvin.
n: moles
Thermodynamic work Formula Questions:
1) If the temperature of a box full of particles that do not interact between then is 1000 K and decrease to 500K, having n=1 mol of those particles, what is the work made by the system?
Answer:
We find the work with the formula:
W = n R ΔT
then,
W = 1 mol*8.314 kg*m2/s2*mol*K *500 K
W = 4157 J
2) The same box before, has made a work of 5000 J, what is the value of the temperature if it started at 100 K?
Answer:
The change of temperature is found from the formula of work:
ΔT= W/(n R)
then,
ΔT = 5000 J /( 1 mol* 8.314 kg*m2/s2*mol*K )
ΔT = 601.4 K = Tf - Ti
Tf = 601.4+Ti = 601.4+100K = 701.4 K
|
Related Links: |