Question

Cesium chloride crystallizes in cubic unit cell with Cl ions at the corners and a Cs⊕ ion in the centre of the cube. How many CsCl molecules are there in the unit cell? ​

Answer 1

In the cesium chloride (CsCl) structure, each unit cell consists of one cesium ion at the center and chloride ions at the corners. As chloride ions are shared among eight cubes, there is effectively one chloride ion per cube. Combined with the central cesium ion, this means there is one CsCl molecule per unit cell.

Step-by-step explanation:

In the structure of cesium chloride (CsCl), each unit cell consists of one cesium ion (Cs+) at the center of an eight cornered cube, and the chloride ions (Cl-) are present at the corners. Now, each unit cube shares its corners with eight adjacent cubes. Thus, each chloride ion is shared among eight cubes. So, the contribution of each chloride to a single cube is 1/8. As there are 8 corners, the total chloride ions per cube is 1 (1/8 x 8). Plus, it has one cesium ion at the center. So, per unit cell, it consists of one Cs+ ion and one Cl- ion. Therefore, we can conclude that there is only one CsCl molecule per unit cell.

Learn more about Cesium Chloride Structure