Solid KF has a lattice energy of 804 kJ/mol and a heat of solution (in water)of -15 kJ/mol.RbF has a lattice energy of 768 kJ/mol and a heat of solution (in water)of -24 kJ/mol.Which salt forms stronger attractions with water?
A)KF,since it has a larger lattice energy.
B)RbF,since it has a smaller lattice energy.
C)KF,since it has a more negative heat of hydration.
D)RbF,since it has a more negative heat of hydration
E)They form equally strong attractions with water,since they both have negative heats of mixing.

Question

Quizplus · Accepted Answer

The heat of solution (hydration) is a measure of the strength of the attraction between an ion and a water molecule. A more negative heat of solution indicates a stronger attraction. Therefore, RbF has a stronger attraction with water since it has a more negative heat of solution (hydration) compared to KF. Even though KF has a larger lattice energy, it is not directly related to the attraction with water molecules.

Solid KF Has a Lattice Energy of 804 KJ/mol and a Heat