A piston$-$cylinder device initially contains $0\mathrm{.}2kg$ of steam at $200$kPa and $300C.$ Now, the steam is cooled at constant pressure until it is at $150C.$

a$.$ Determine the volume change, $V(m^3),$ of the cylinder during this process using steam tables.

b$.$ Knowing that the compressibility factors, $Z_1=0\mathrm{.}9956$ and $Z_2=0\mathrm{.}9897$ calculate the volume change, $V(m^3),$ and compare the result to part $a.R=0\mathrm{.}4615$kPa$*\frac{m}{k}g*K$