In equation δhsoln=δh1+δh2+δh3 which of the energy terms for dissolving an ionic solid would correspond to the lattice energy?

The dissolution of a solute in a solvent to form a solution usually occur in three steps, which are delta H1, delta H2 and delta H3. 
For dissolving an ionic solid, the lattice energy, which is the energy that is holding the ionic particles in place correspond to DELTA H2 and it is the energy that must be conquered. The higher the charge in the ionic solid, the higher the lattice energy. The lattice energy must be overcome in order for the solid to dissolve.

Yes it would be a physical change.

Idon't know hope someone you