Question

Calculate the work done when $2moles$ of hydrogen expand isothermally and reversibly at $25{}^{\circ }C$ from $15to45litres$.

• A. $-1309calories$
• B. $-14.36calories$
• C. $-2872calories$
• D. $-28.72calories$

Answer 1

The correct option is A $-1309calories$

Work done in an isothermal reversible process is given as,
$w=-2.303nRTlog\frac{V_2}{V_1}$
Given : $V_1=15L$
$V_2=45L$
$n=2mol$
$R=2cal/K.mol$
$T=298K$
So,
$w=-2.303\times 2\times 2\times 298\times log\frac{45}{15}$
$w=-2745.1\times log3$
$w=-1309.7cal$