Question

Lithium Iodide Has A Lattice Energy Of −7.3×102kJ/mol And A Heat Of Hydration Of −793kJ/mol. Lithium iodide has a lattice energy of −7.3×102kJ/mol and a heat of hydration of −793kJ/mol.Part AFind the heat of solution for lithium iodide.Express your answer using one significant figure.ΔHsoln = kJ/mol Part BDetermine how much heat is evolved or absorbed when 40.0 g of lithium iodide completely dissolves in water.Express your answer using one significant figure.|q| = kJ Part CIs the heat evolved or absorbed?Is the heat evolved or absorbed?evolvedabsorbed

Answer 1

Heat of solution= - 63KJ/mole

Heat evolved = - 18.82KJ

Explanation:Heat of solution = Heat of solute + Heat of hydration

◇Hsoln = - ( - 7.3 × 10 ^ 2) + ( - 793 ) KJ / mol

◇H soln= - 63 KJ

Use enthalpy of solution equation to determine the enthalpy of solution for LiI

LiI ---> Li^ + + I^-

Molecular mass of LiI=133.85g

The chemical equation for the dissociation will be:

40gLiI (1molLiI)/133.85g LiI - 63KJ/1 mol LiI

18.82KJ

The heat was evolved because the value of enthalpy was negative