In: Chemistry
Given the following thermodynamic data, calculate the lattice
energy of CsF:
ΔH°f[CsF(s)] = -554 kJ/mol
ΔH°sublimation [Cs] = 76.5 kJ/mol
Bond energy [F-F] = 159 kJ/mol
IE1 (Cs) = 376 kJ/mol
EA1 (F) = -328 kJ/mol
-1414 kJ/mol
-1493 kJ/mol
-714 kJ/mol
-758 kJ/mol
-837 kJ/mol
Cs(s) + 1/2F2(g) --------------> CsF(s) ΔH°f[CsF(s)] = -554 kJ/mol
sublimation energy
Cs(s) ------------------> Cs(g) ΔH°sublimation [Cs] = 76.5 kJ/mol
Cs(g) --------------> Cs^+ (g) + e^- IE1 (Cs) = 376 kJ/mol
bond dissociation energy
F2(g) ---------------> 2F(g) Bond energy [F-F] = 159 kJ/mol
1/2F2(g) ---------------> F(g) Bond energy [F-F] = 159/2kJ/mol = 79.5Kj/mole
electron affinity
F(g) + e^- -------------->F^- (g) Bond energy [F-F] = -328 kJ/mol
lattice energy
Cs^+(g) + F^- (g) -----------------> CsF(s) ΔH° lattice =
from Hess law
ΔH°f[CsF(s)] = ΔH°sublimation [Cs] + IE1 (Cs) + Bond energy [F-F] + Bond energy [F-F] + ΔH° lattice
-554 = 76.5 + 376 + 79.5 -328+ ΔH° lattice
ΔH° lattice = -758Kj/mole >>>>answer
-758 kJ/mol >>>.answer