Question

What are the coordination numbers of li+ and s2− in the lithium sulfide crystal shown? enter the values in order of li+ and s2−, respectively?

Answer 1

Answer:    
As there must be twice as many lithium ions as sulphide ions, the 'numbers'
must be different. 
 It's 4:8. i.e. 4 sulphides around each lithium; and 8 lithiums around each
sulphur. 
 It's an antifluorite structure.

Answer 2

In the lithium sulphide crystal, coordination number of ${\mathbf{L}}{{\mathbf{i}}^{\mathbf{+}}}$is 4 and the coordination number of ${{\mathbf{S}}^{{\mathbf{2-}}}}$is 8.

Further explanation:

Crystal structure or lattice is the three-dimensional representation of atoms and molecules arranged in a specific manner. The unit cell is the tiniest part of the lattice that is repeated in all directions to yield the crystal lattice. There are 3 major types of cubic unit cells as follows:

1. The simple cubic unit cell (sc)

2. Body-centered unit cell (bcc)

3. Face-centered unit cell(fcc)

The crystal lattice formed by ${\text{L}}{{\text{i}}^+}$ and ${{\text{S}}^{2-}}$ is an antifluorite structure in which ccp/fcc unit cell is formed by anions and cation are present in all tetrahedral voids.

Ions present in tetrahedral void has a coordination number 4, therefore, ${\text{L}}{{\text{i}}^+}$ has coordination number 4.

${\text{L}}{{\text{i}}^+}$has +1 charge and ${{\text{S}}^{2-}}$has -2 charge. Therefore the ratio of cation to anion is 1:2 thus the coordination number of anion must be twice of cation thus it is 8.

Learn more:

1. Determine molecules and polyatomic ions that cannot be adequately described using a single lewis structure.:brainly.com/question/6786947

2. Determine the correct structure of  : brainly.com/question/9422880

Answer details:

Grade: Senior school

Subject: Chemistry

Chapter: Solid state

Keywords: Solid state, coordination number, Li+, S2-, lithium sulfide crystal, unit cell, simple cubic unit cell, body centered unit cell and face centered unit cell.