An ionic compound dissolves easily in water because a.) the ionic lattice collapses.
b.) the ions changed their composition.
c.) the ions are separated by the water molecules in the solution.
d.) the ionic lattice becomes disordered. I

I say C.

Explanation:

Ionic compounds dissolve in water if the energy given off when the ions interact with water molecules compensates for the energy needed to break the ionic bonds in the solid and the energy required to separate the water molecules so that the ions can be inserted into solution.

Hope it helps!~ (Sorry if you get it wrong or I got it wrong-)

~The Confuzzeled homan