Answer
Please see the work below.
Work Step by Step
According to sign convention, the energy taken or added to a process is taken as positive. The energy released during a process is taken as negative.
The lattice energy of an ionic compound is the enthalpy change that occurs when one mole of the ionic compound dissociates into ions in the gaseous state. It is the energy required to break bonds into ions. Bond breaking is always accompanied by the absorption of energy.
During the hydration process, new bonds are formed between ions and polar water molecules. The bond formations always is accompanied by the release of energy.
