Consider an ideal gas enclosed in a 1.00 L container at an internal pressure of
ID: 867112 • Letter: C
Question
Consider an ideal gas enclosed in a 1.00 L container at an internal pressure of 10.0 atm. Calculate the work, w, if the gas expands against a constant external pressure of 1.00 atm to a final volume of 15.0 L. Number w = 15 J Now calculate the work done if this process is carried out in two steps. 1. First, let the gas expand against a constant external pressure of 5.00 atm to a volume of 3.00 L. 2. From there, let the gas expand to 15.0 L against a constant external pressure of 1.00 atm. Number w = JExplanation / Answer
Solution :-
Formula to calculate the work done at constant pressure is as follows
W= - P delta V
Delta V is the change in the volume
Lets first calculate the work done when gas expands from 1.00 L to 15.0 L at 1.00 atm
W= - 1.00 atm * (15.0 L – 1.00L)
W= -14 L atm
Now lets convert L atm to Joules
1 L atm = 101.325 J
-14 L atm * 101.325 J / 1 L atm = -1488 J
Therefore work done = -1488 J
Part 2 calculating work done in 2 steps
Step 1 at constant pressure 5 atm from 1 L to 3.00 L
W= -5 atm * (3.00 L – 1.00 L)
W= -10 L atm
Converting to Joules
-10 L atm * 101.325 J / 1 L atm = -1013 J
Now calculating at 1 .00 atm from 3.00 L to 15.0 L
W= -1.00 atm * (15.0 L – 3.00 L)
W= -12 L atm
Converting to Joules
12 L atm * 101.325 J / 1 L atm = -1216 Joules
Therefore total work done = -1013 J + (-1216 J) = -2229 J
So total work done = -2229 J