Calculate the number of Schottky defects per cubic meter in potassium chloride at 350 and 700 C. The energy required to form each Schottky defect is 2.6 eV, while the density for KCl is 1.955 g/cm. Molecular weights of K and Cl are 39.10 and 35.45 g/mol, respectively. Avogadro's number is 6.023x1023 atoms/mol and Boltzmann's constant is 8.62x105 eV/K. (10) Calculate the number of Schottky defects (Ns) per cubic meter in potassium chloride at 450 C. The energy (Qs) required to form each Schottky defect is 2.6 eV, while the density for KCI at 450 C is 1.955 g/cm3. Molecular weights of K and Cl are 39.10 and 35.45 g/mol, respectively. Avogadro's number, Na, is 6.023x1023 atoms/mol and Boltzmann's constant, k, is 8.62x10-5 eV/K. Solution: First, we must compute the value of number of lattice sites per cubic meter, N: (6.023x102atoms / mol)(1.955g/ cm )(10cm / m (39.10 +35.45)(g / mol) N.p = 1.58x1028 Lattice sites per N Ag + Ac cubic meter. Now, incorporating this value into Equation below, leads to the following value for Ns. N, = Nexp[-2xT) 2.6 = (1.58x102*) exp 2(8.62.x10)(450+ 273) N. = 1.38x10" defects / m' Number of Schottky defects %3D (a) Schottky defect