Please help me with this question

What are the factors that affect the resistance of a wire?

2kg of refrigerant 134a undergoes a polytropic process in a piston-cylinder assembly from an initial state of saturated vapor at 2 bar to a final state of 12 bar, 80 degree c. a)determine the work for the process in kj. b)sketch the process on a p-v diagram.

Explain what happens at the saturation point when adding salt to water at room temperature.