Question

$1$ mole of an ideal gas expand isothermally and reversibly from a pressure $7$ atm to $1$ atm at $25^{\circ}C$. What will be the total work done by the system?

• A. $-4822\,J$
• B. $4822\,J$
• C. $3915 \,J $
• D. $-3915 \,J $

Answer 1

Answer: (A)

Work done by the system
$ = -2.303 \,nRT\,log \frac{P_1}{P_2}$
$= - 2.303 \times 1 \times 8.314 \times 298\,log \frac{7}{1}$
$ = -2.303 \times 1 \times 8.314 \times 298 \times 0.845 $
$ = -4822\,J$