Establish whether the system is an open (control volume) or closed system-recall that open and closed relates to matter (working substance) crossing the system's boundaries.

Specify whether the event being examined constitutes a process or cycle.

Determine the phase region in which the working substance is situated.

Identify and apply the physical principles (commonly Newton's second law of motion, the first and second laws of thermodynamics, and conservation matter) that give insight to the problem.

Introduce working substance property relationships and process or cycle specifications.

Achieve a solution and reflect to see if the answer makes sense.

In the single phase region the substance has two degrees of freedom, i.e., two properties such as p and T may be independently varied.

If two phases are in equilibrium, each phase component loses one degree of freedom, i.e., pressure and temperature become dependent and specifying one establishes all other properties such as density and viscosity.

If three phases coexist, the molecular state of each phase component is fixed, i.e., each phase has zero degrees of freedom and only the amount of each phase can be varied.

For most processes involving pure solids or liquids, the density and...