Answer to Question #75287 in General Chemistry for pooja

Question

Calculate the lattice energy (in Units kJ mol1
) for ZnO crystal using Eq. 3.4 based on
electrostatic model and using a Born-Haber cycle. Compare the two answers and comment
on any difference.
Useful data:
Medelung constant (A) = 1.6411
Born Constant (n) = 8
Internuclear distance (a) = 199 pm
Zn(s) + ½ O2(g)  ZnO(s) Hf =  350.5 kJ mol1
Zn(s)  Zn(g) HS = 130.4 kJ mol1
Zn(g)  Zn+
(g) I(Zn) = 906.3 kJ mol1
Zn+
(s)  Zn2+(g) I(Zn+
) = 1733 kJ mol1
½ O2(g)  O(g) ½Hd = 248.5 kJ mol1
O(g)  O

(g) EA(O) = 141 kJ mol1
O
-
(g)  O
2
(g) EA(O
) = 780 kJ mol1
(6)