Many ionic compounds dissolve in water, whether ornot depends on the energy changes involved.
1. ion separation
2. ion hydration (surrounding ions by water molecules)
The electrostatic attractions between oppositely charged ions are overcome by the small charge on a water molecule. Water is made up from hydrogen and oxygen which have different electronegativities.
The negative end of a water dipole is attracted to a positive ion in the lattice and pulls it away. It is then surrounded by other water molecules that align themselves around the positively charged ion with the negative dipole facing it.
Vice versa for the negative ions!
The ions are said to be hydrated.
Comments
No comments have yet been made