7. (a) Determine the crystal lattice energy for LiF(s) given that the ∆Hsubl for Li = 155kJ/mol,

Question

∆H0f for F(g) = 78.99kJ/mol, IE1 of Li = 520kJ/mol, EA for Fluorine = -322kJ/mol and the ∆H0f LiF(s) = -589.5kJ/mol
(b) For the following reactions:
NH4NO3(s) + H2O(l) �¨ NH4+(aq) + NO3-(aq). Given that
∆H0f of NO3- = ∆H0f = 205.0kJ/mol, and S0 = 146J/mol .k,
∆H0 f of NH4+ = -132.57kJ/mol, and S0 = 113.4 J/mol .k,
∆H0 f of NH4NO3 = -365.56kJ/mol, and S0 = 151.08 J/mol .k

Answer 1

DHsubl + IP + DHF + EA(negative) + U = -589.5
Solve for U.