Chemistry: what exactly happens when an ice cube melts in warm water?When analyzing an ice cube melting in warm water, what exactly is happening at...

According to kinetic theory particles (atoms, molecules)
are in constant thermal motion unless at absolute zero. Molecules of water have
attraction forces between them, and if the molecules aren't moving much i.e. they are
very cold, the forces can bond the molecules together - you have ice. When you put ice
into (warmer) liquid water the molecules in the ice begin to move (actually a type of
wobbling) more and more until the bonds are broken and the ice
melts.

At a deeper level, just at the temperature when the
bonds get broken the molecules move slightly further apart without wobbling more even
though the attractive forces are still there. This is analogous to lifting something
higher above the Earth - you give it potential energy. The potential energy to do this
has come from the warm water. The energy needed to do this is called latent heat. After
the molecules break apart any extra energy causes the molecules to wobble faster - they
have gained kinetic energy.

To find the molar heat of
vaporization of water take 18 grams of water and heat it just to boiling point. Then
continue heating with a heater that can have its energy output measured. Keep heating
until all of the water has boiled away. The energy supplied by the heater to cause the
boiling only is the molar heat of vaporization of water.