The energy released when Na + (g) and Cl - (g) form NaCl (s) is 778. kJ/mol. Approximately 162. J is absorbed from the surroundings when 2.35 g of NaCl is completely dissolved in water. What is the enthalpy of hydration of NaCl?

Answer: - 777.838

Explanation:

Given data,

Lattice energy (energy released to form NaCl) = 778 kJ/mol

Heat of solution = 162 Joules

= 0.162 kJ (converted to kilojoules)

Substitute the values in the given formula,

Enthalpy of hydration = ΔHsolution - ΔHlattice energy

= 0.162 - 778

Therefore, Enthalpy of hydration = - 777.838