Match List I with List II

Choose the correct answer from the options given below:

A-III, B-IV, C-I, D-II

The correct answer is option 4. A-III, B-IV, C-I, D-II.

Let us delve into more detail about the crystal structures of the substances mentioned in List I:

A. Cubic:  Zinc blende \((ZnS)\) has a cubic crystal structure. In the zinc blende structure, the atoms are arranged in a face-centered cubic \((fcc)\) lattice, where each atom is positioned at the center of a cube and at the center of each face of the cube.

B. Triclinic:  Potassium dichromate \((K_2Cr_2O_7)\) has a triclinic crystal structure. Triclinic is one of the seven crystal systems, characterized by three unequal axes and angles not necessarily equal to 90 degrees. In the case of potassium dichromate, the arrangement of potassium, chromium, and oxygen atoms within the crystal exhibits triclinic symmetry.

C. Hexagonal: Graphite has a hexagonal crystal structure. In graphite, carbon atoms are arranged in layers with a hexagonal pattern. Each carbon atom is bonded to three others in a planar hexagonal arrangement within a layer. The layers are held together by relatively weak van der Waals forces, allowing them to slide over each other easily.

D. Tetragonal: White tin \((Sn)\) has a tetragonal crystal structure. White tin is the stable form of tin at temperatures above 13.2 degrees Celsius. In the tetragonal structure, the tin atoms are arranged in a lattice with a fourfold symmetry axis, and the lattice parameters are different along two perpendicular axes.

In summary:
A. Cubic: Zinc blende has a cubic crystal structure (III).
B. Triclinic: Potassium dichromate has a triclinic crystal structure (IV).
C. Hexagonal: Graphite has a hexagonal crystal structure (I).
D. Tetragonal: White tin has a tetragonal crystal structure (II).

Therefore, the correct match is 4. A-III, B-IV, C-I, D-II.