Problem $3(18$ pts $)$: A rigid tank begins with $4$ kg of $R-134a$ at $900$ kPa and $50C\mathrm{.}1$

kg of $R-134a$ is added to the tank through a valve. This $R-134a$ is a saturated

mixture at $1400$ kPa and a quality of $0\mathrm{.}5.$ The tank is heated from a source at

$300C$ and the system ends with a temperature of $70C.$

a$)$ Determine the final system pressure

b$)$ Determine the amount of heat added $[$ANSWER: $133\mathrm{.}4$ kJ $]$

c$)$ Determine the entropy generated by the process $[$ANSWER: $0\mathrm{.}1982k\frac{J}{K}]$