which produces the greatest entropy increase?

melting the solid
heating the solid
heating the liquid
heating the gas
vaporizing the liquid

is it melting the solid?

1 answer

The question has broad limits because no concrete details are given; however, melting the solid probably is higher than #2,3,and 4. I think vaporizing the liquid is the greatest. If you have a particular substance in mind, delta S = (delta Q/T). Water, for example, is heat fusion/273 for melting ice to liquid and heat vaporization/373 for vaporization.