Problem $2(30$ points$)$

A rigid tank having a volume of $0\mathrm{.}3$ m $3$ initially contains water as two$-$phase liquid vapor mixture at $\backslash (260^\{\backslash$circ$\}\backslash$mathrm$\{$C$\}\backslash )$ with a quality of $0\mathrm{.}7.$ Saturated water vapor at $\backslash (260^\{\backslash$circ$\}\backslash$mathrm$\{$C$\}\backslash )$ is slowly withdramen through a pressure$-$regulating valve at the top of the tank as energy is transfenred by heat to maintain the pressure constant in the tank. This continues until all remaining in the tank is saturated water vapor at $\backslash (260^\{\backslash$circ$\}\backslash$mathrm$\{$C$\}\backslash ).$ Neglecting all kinetic and potential energy effects, determine the following

$(3$pt$)($a$)$ Initial mass of water occupying the tank.

$(2$pt$)($b$)$ Final mass of water occupying the tank.