The pyknometric density of sodium chloride crystal is

2.165 × 103 kg m-3, while its X – rays density is 2.178 × 103kg m-3

The fraction of unoccupied sites in sodium chloride crystal is


Correct option is

5.96 × 10-3


Difference = 2.178 × 103 – 2.165 × 103 = 0.013 × 103





The number of atoms in 100 g of an fcc crystal with density,

d = 10g/ cm3 and cell edge equal to 100 pm, is equal to


The number of unit cell in 58.5 g of NaCl is nearly


Analysis shows that an oxide ore of nickel has formula Ni0.98O1.00. The percentage of nickel as Ni3+ ions is nearly


In orthorhombic, the value of a, b and c are respectively 4.2, 8.6 and8.3. given the molecular mass of the solute is 155 g mol-1 and that of density is 3.3 g/cc, the number of formula units per unit cell is


A solid has a structure in which ‘W’ atoms are located at the corner of a cubic lattice ‘O’ atoms at the centre of edge and Na atoms at the centre of the cube. The formula for the compound is


Ferrous oxide has a cubic structure and each edge of the unit cell is 5.0. Assuming density of the oxide as 4.0 g/cm-3, then the number of Fe2+ and O2- ions present in each unit cell will be


In a solid ‘AB’ having the NaCl structure, ‘A’ atoms occupy the corners of the cubic unit cell. If all the face – centred atoms along one of the axes are removed thye the resultant stoichiometry of the solid is


The following is not a function of an impurity present in a crystal