Phase change flatlines

A New Year’s Eve Chemistry Karaoke challenge. Examine the picture below which shows a heating curve for ice through to steam. The challenge is to come up with karaoke lyrics to popular songs of your choice which fit the regions on the curve 1 to 5 describing the behaviour of the water molecules. Students often have difficulty in explaining why the temperature does not increase during the regions of the curve representing phase changes; solid ice to liquid water (2.) and liquid water to gaseous steam (4.). Thus, the added challenge is to explain the reasons for these ‘flatlines’ in your karaoke lyrics.