Calculating Isothermal Expansion Work - 2 Moles Ideal Gas, 380K

In summary, the question is asking for the work done by a gas that expands isothermally from a temperature of 380 K to 3 times its initial volume. The formula W = nRT ln (Vf/Vi) can be used to solve this problem, with n = 2, R = 8.31, T = 380, Vi = initial volume, and Vf = final volume. By substituting the given values and solving for Vf, the final volume is found to be 3 times the initial volume. Therefore, the work done by the gas is equal to nRT ln (3).
  • #1
BlackMamba
187
0
Hello,

I have what should be an easy problem, but I, of course, am having some issues.

Here's the problem: The temperature of 2 moles if an ideal gas is 380 K. How much work does the gas do in expanding isothermally to 3 times its initial volume?

So I know I'm going to to need to use this equation to find the work done:
[itex]W = nRT ln (\frac{V_f}{V_i})[/itex]

I know that:

n = 2
R = 8.31
T = 380
Vi = (3)Vi
Vf = ?

I'm hung up on the volume portion of this problem. I don't have an initial or final volume and that's what I can't seem to work around. Any help would be greatly appreciated.

Thanks in advance.
 
Last edited:
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  • #2
Vi = Vi
Vf = 3 Vi
since it expands three times its initial volume
 
  • #3
please correct vi=3.vi to be vf=3 vi, so now the problem is solved..
 
  • #4
W = nRTln(3)

(Vf/Vi ) = 3Vi/Vi = 3
 
  • #5
Oh Lord. Something so simple that I couldn't put together. Thank you everyone for your reply. It is greatly appreciated. :)
 
  • #6
simple

:rofl:
BlackMamba said:
Hello,

I have what should be an easy problem, but I, of course, am having some issues.

Here's the problem: The temperature of 2 moles if an ideal gas is 380 K. How much work does the gas do in expanding isothermally to 3 times its initial volume?

So I know I'm going to to need to use this equation to find the work done:
[itex]W = nRT ln (\frac{V_f}{V_i})[/itex]

I know that:

n = 2
R = 8.31
T = 380
Vi = (3)Vi
Vf = ?

I'm hung up on the volume portion of this problem. I don't have an initial or final volume and that's what I can't seem to work around. Any help would be greatly appreciated.

Thanks in advance.
vfinal=3vinitial
 

1. What is isothermal expansion work?

Isothermal expansion work is the work done by a gas during a process where the temperature remains constant. It is calculated by multiplying the change in volume by the pressure of the gas.

2. How do you calculate isothermal expansion work for 2 moles of an ideal gas?

To calculate isothermal expansion work for 2 moles of an ideal gas, you would use the formula W = nRT ln(V2/V1), where W is the work, n is the number of moles, R is the gas constant, T is the temperature in kelvin, and V2 and V1 are the final and initial volumes, respectively.

3. What is the ideal gas law and how is it related to isothermal expansion work?

The ideal gas law is a mathematical equation that describes the behavior of an ideal gas. It states that the product of pressure and volume is directly proportional to the temperature and number of moles of gas. This law is used in the calculation of isothermal expansion work.

4. How do you convert temperature from degrees Celsius to Kelvin?

To convert temperature from degrees Celsius to Kelvin, you would add 273.15 to the temperature in degrees Celsius. This is because the Kelvin scale starts at absolute zero, which is -273.15 degrees Celsius.

5. Can isothermal expansion work be negative?

Yes, isothermal expansion work can be negative. This occurs when the gas loses energy during the process, resulting in a decrease in volume. In this case, the work done by the gas would be negative, indicating that the gas is losing energy.

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