Please Solve this problem with detiles, don't forgot pv diagram...

A mass of 5kg of saturated liquid-vapor mixture of H2O is contained in a pistoncylinder device at 100kPa. Initially, 2kg of the H2O is in the liquid phase and the rest is in the vapor phase. Heat is now transferred to the H2O, and the piston, which is resting on a set of stops, starts moving when the pressure inside reaches 125kPa. Heat transfer continues until the total volume triples. Determine: a) The mass of liquid H2O when the piston first starts moving b) The work done during this process. Also, show the process on a P - v diagram with respect to saturation lines