In a cubic unit cell of an ionic compound, the eight corners are occupied by anions and cations at the center of the cube. Calculate the volume of the unit cell if density of the unit cell is 4 g cm ⁻³ . [Molar mass of compound = 168.6 g mol ⁻¹ and N_A = 6.022 10²³ ]

Step-by-step solution

Number of anions per unit cell = 8 1 8 = 1 Number of cations per unit cell = 1 Total number of formula units per unit cell, Z = 1 The density of the unit cell is given by the formula: d = Z M N_A V Rearranging for volume V : V = Z M N_A d Substituting the given values: V = 1 168.6 6.022 10²³ 4 V = 168.6 24.088 10²³ V = 7.0 10⁻²³ cm ^3 Answer: 7.0 10⁻²³ cm ^3