An unconstrained piston/cylinder assembly with a massless piston is oriented upright in an environment in which the surrounding pressure is 100 kPa. The piston/cylinder contains R134. At the original state, the R134 is a saturated liquid. Heat is added until the R134 becomes a saturated vapor. What type of process is this? What is the temperature at the initial state (state 1)? What is the temperature at the final state (state 2)? How much heat is required to achieve the process? Clearly indicate which table(s) you are using for any property values you may need.