Question

5 mol of liquid water is compressed from 1 bar to 10 bar at constant temperature. Change in Gibb's energy $\left(\Delta G\right)$ in Joule is: (Density of water $=1000kg/m^3)$

• A. 18
• B. 225
• C. 450
• D. 900

Answer 1

The correct option is D 900

$dG=VdP-SdT$
at constant T.
$dG=VdP$
$\because$ for $H_{2}O$ volume will be almost constant on increasing pressure.
$\therefore \Delta G=V\left(\Delta P\right)$
$\Delta G=V(P_2-P_1)=5\times 18\times {10}^{-6}(101-1)\times {10}^{5}Joule=5\times 18\times {10}^{-1}\times {10}^2=900Joule$.