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) They form equally strong attractions with water, because they both have negative heats of mixing.
B) KF, because it has a more exothermic lattice energy
C) RbF, because it has a more negative heat of hydration
D) KF, because it has a more negative heat of hydration
E) RbF, because it has a less exothermic lattice energy

Question

Quizplus · Accepted Answer

The heat of solution reflects the net effect of breaking the lattice energy and forming attractions with water (hydration energy). RbF's more negative heat of solution indicates stronger attractions with water, as it suggests a greater release of energy upon hydration.

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