Solid State

A diatomic molecule X₂ has a body centered cubic (bcc). The density of the molecule is 6.17 g cm⁻³. The number of molecules present in 200 g² of X₂ is: (Avogadro constant (NA) = 6 * 10²³ mol⁻¹)

A crystal is made up of metal ions ' M₁ ' and ' M₂ ' and oxide ions. Oxide ions form a ccp lattice structure. The cation ' M₁ ' occupies 50% of octahedral voids and the cation ' M₂ ' occupies 12.5% of tetrahedral voids of oxide lattice. The oxidation numbers of ' M₁ ' and ' M₂' are respectively:

An element with molar mass 2.7 * 10?² kg mol?¹ forms a cubic unit cell with edge length 405pm. If its density is 2.7 * 10³ kg m?³, the radius of the element is approximately * 10?¹² m (to the nearest integer).

In an estimation of bromine by Carius method, 1.6 g of an organic compound gave 1.88 g of AgBr. The mass percentage of bromine in the compound is [numerical value] (Atomic mass, Ag=108, Br=80 g mol?¹)

If AB? molecule is a polar molecule, a possible geometry of AB? is

An element crystallises in a face-centred cubic (fcc) unit cell with cell edge a. The distance between the centres of two nearest octahedral voids in the crystal lattice is:

The parameters of the unit cell of substance are a = 2.5, b= 3.0, c=4.0, α = 90°, β =120°, γ = 90°. The crystal system of the substance is:

The coordination number of an atom in a body- centred cubic structure is___________.

 [Assume that the lattice is made up of atoms]

The number of octahedral voids per lattice site in a lattice is………. (Rounded off to the nearest integer)