Question

Water expands when it freezes. Determine amount of work in joules, done when a system consisting of $1.0L$ of liquid water freezes under a constant pressure of $1.0atm$ and forms $1.1L$ of ice.

Answer 1

The workdone $=-P_{\left[ext\right]}dV=-P\Delta V$

$V_{final}=$Volume of ice$=1.1L$

$V_{initial}=$Volume of water$=1.1L$

$\Delta V=V_{final}-V_{initial}=1.1-1.0=0.1L$

Workdone$=-P\Delta V=-[1.0\times 0.1]=-0.1Latm=-10.1J$ (1 L atm=101.32J)