How much work is done by the system when
2.00 moles of O2 expand from a volume of
3.00 liters to a volume of 5.1 liters against a
constant external pressure of 0.0100 atm?
Answer in units of J.
I get w=-p(deltaV) but what about moles?
Do you really care how many moles are there? 1 mol expanding or 100 mols expanding, the only thing that counts is volume difference and p.
The thing is I tried the negative p delta v on my UT homework, and it didn't accept so I thought maybe moles had something to do with it. Unless I was doing the equation wrong.
Did you use -p(Vfinal-Vinitial)
0.0100(5.1-3) = ? L*atm. The problem wants joules, convert by
L*atm x 101.325 = ?J.
Work should be a negative value; make sure to include the - sign when you enter into the database. Keep me posted.
To calculate the work done by the system, you can use the formula:
W = -P * ΔV
Where:
W is the work done by the system
P is the external pressure
ΔV is the change in volume
In this case, you already have the external pressure (P = 0.0100 atm) and the change in volume (ΔV = 5.1 L - 3.0 L = 2.1 L), but you need to convert the volume from liters to moles.
To convert the volume from liters to moles, you can use the ideal gas law equation:
PV = nRT
Where:
P is the pressure
V is the volume
n is the number of moles
R is the ideal gas constant
T is the temperature
Since you have the values for P, V, and n, you can rearrange the equation to solve for n:
n = PV / RT
Now, you need to rearrange the equation to solve for V in terms of moles:
V = nRT / P
Substituting the given values:
P = 0.0100 atm
V = 3.00 L
Now, you can calculate n:
n = (3.00 L * 0.0100 atm) / (R * T)
Since the temperature (T) and the ideal gas constant (R) are not given in the question, we cannot calculate the exact number of moles. You would need to have the temperature and the ideal gas constant to perform this calculation.
However, once you have the number of moles, you can substitute the values into the work equation to determine the answer in units of joules.