Ice crystallizes in a hexagonal lattice having the volume of the unit cell as $132\times {10}^{-24}$ $c{m}^3$. If the density is 0.92 g/cm³ at a given temperature, then the number of H₂O molecules per unit cell is : 

1. 1

2. 2

3. 3

4. 4

AB crystallizes in a body-centred cubic lattice with edge length a equal to 387 pm. The distance between two oppositely charged ions in the lattice will be : 

1. 250 pm

2. 200 pm

3. 300 pm

4. 335 pm

In a face centred cubic lattice, atom A occupies the corner positions and atom B occupies the face
centre positions. If one atom of B is missing from one of the face centred points, the formula of the compound is

1.AB₂

2.A₂B₃

3.A₂B₅

4.A₂B

Percentage of free space in cubic close packed structure and in body centered packed structure are respectively:

1. 48% and 26%

2. 30% and 26%

3. 26% and 32%

4. 32% and 48%

Packing fraction of simple cubic crystal lattice is 

1. 38%

2. 74%

3. 68%

4. 52.4%

In which of the following crystals are alternate tetrahedral voids occupied:

1. NaCl

2. ZnS

3. CaF₂

4. Na₂O

In a metal oxide, the oxide ions are arranged in hexagonal close packing and metal ions occupy two third of the octahedral voids. The formula of the oxide is : 

1. MO

2. M₂O₃

3. MO₂

4. M₂O

A crystal is made of particle X, Y & Z. X forms FCC packing, Y occupies all octahedral

voids of X and Zoccupies all tetrahedral voids of X, if all the particles along one body

diagonal is removed then the formula of the crystal would be –

(1) XYZ₂

(2) X₂YZ₂

(3) X₅Y₄Z₅

(4) X₅Y₄Z₈

In a hypothetical solid C atoms are found to form cubical close packed lattice. Aatoms occupy all tetrahedral vioids& B atoms occupy all octahedral voids. A and B atoms are of appropriate size, so that there is no distortion in CCP lattice of C atoms. Now if a plane as shown in the following figure is cut.

Then the cross section of this plane will look like.

(1)

(2)

(3)

(4)

In hexagonal close packing of sphere in three dimensions.

(1) In one unit cell there are 12 octahedral voids and all are completely inside the unit cell.

(2) In one unit cell there are six octahedral voids and all are completely inside the unit cell.

(3) In one unit cell there are six octahedral void and of which three are completely inside the unit cell and other three are partially inside the unit cell.

(4) In one unit cell there are 12 tetrahedral voids, all are completely inside the unit cell.