Question

Calculate w for the isothermal reversible expansion of 1mol of an ideal gas from an initial pressure of 1.0 bar to a final pressure of 0.1 bat at a constant temperature at 237 k.

• A. -5227.2 J
• B. +52272.2 J
• C. +2257 J
• D. None of these

Answer 1

Answer: (C)

+2257 J

Solution:-

As we know that, work done for isothermal reversible expansion is given by-

$W=-nRT\ln \frac{P_i}{P_f}$

Given:-

$n=1\text{mol}$

$P_i=1.0\text{bar}$

$P_f=0.1\text{bar}$

$T=237K$

$R=8.314J$

$\therefore W=-1\times 8.314\times 237\times \ln \frac{1}{0.1}$

$\Rightarrow W=-2.303\times 8.314\times 237\times \log 10$

$\Rightarrow W=-4537.87J$