Concise Physical Chemistry

c11 JWBS043-Rogers September 13, 2010 11:26 Printer Name: Yet to Come

PROBLEMS AND EXERCISES 181

Problem 11.6

How many atoms are there in the unit cell in Fig. 11.15?

Problem 11.7

(a) Ifris set to 1.0 arbitrary length units, what is the volume of the unit cell in

Fig. 11.15?

(b) What is the volume of the atoms within the unit cell in Fig. 11.15?

(c) What is the packing efficiency?

Problem 11.8

What is the lattice energy (enthalpy) of NaCl?

Take information on Na+from Example 11.1. The enthalpies of dissociation and

ionization of Cl−are 121.8 and−351.2 kJ mol−^1 , respectively. The standard enthalpy

of formation of NaCl is−411.2 kJ mol−^1.