Q12.128CP

Question



Like most transition metals, tantalum (Ta) exhibits several oxidation states. Give the formula of each tantalum compound whose unit cell is depicted below:


a.




b.




Step-by-Step Solution

Verified
Answer
  1. The formula of the compound is TaN.
  2. The formula of the compound is TaC.
1Step 1: Definition

The matter exists in three phases- solid, liquid, and gaseous. The solid-state molecules are arranged in a three-dimensional structure having a high force of attraction. The solid molecule can be arranged in two forms- crystalline and amorphous solid.


Crystalline solids have the same structure throughout the molecule in the three-dimensional structure. The crystalline solid has a well-arranged structure.

Amorphous solids have a different arranged structure in throughout the molecule in the three-dimensional structure. The amorphous has a weak force of attraction.

A cubic unit cell can be defined as a three-dimensional structure having the same length of sides.

 

 

2Step 2: Subpart (a) The formula of tantalum compound whose unit cell is been depicted as A.

In the cubic lattice,

The Ta-atom is present at the corner which is touched by the 8 atoms in the unit cell and at body centre one atom present at the centre of the unit cell.

 The number of Ta-atoms  in the unit cell =(1×1) + (8×18)The number of Ta-atoms in the unit cell =1+1The number of Ta-atoms in the unit cell =2

 

 

In this unit cell, one N atom inside the unit cell and 4 N-atom are present at  14 edge centre.

 The number of N-atoms in the unit cell = (1×1)+(4×14)The number of N-atoms in the unit cell = 1+1The number of N-atoms in the unit cell = 2

 

In the compound, the Ta-atom is present at the corner and body-centre forming Ta-atom having co-ordination number 2 whereas the N-atom are present at edge centre having co-ordination number is 2.

Therefore, the formula of the compound is TaN.

 

3Step 3: Subpart (b) The formula of tantalum compound whose unit cell is been depicted as B.

In the cubic lattice,

The Ta-atom is present at edge-centre which is touched by the 4 atoms in the unit cell and at body centre one atom present at the centre of the unit cell.

 

 The number of Ta-atoms in the unit cell = (1×1)+(12×14)The number of Ta-atoms in the unit cell = 1+3The number of Ta-atoms in the unit cell = 4

 

In this unit cell, one C-atom inside the unit cell and 8 C-atom are present at  18 corner and 6 C-atom present at  12 face-centre.


The number of C-atoms in the unit cell = (8×18)+(6×12)The number of N-atoms in the unit cell = 1+3The number of N-atoms in the unit cell = 4


In compound, the Ta-atom are present body-centre and edge-centre forming Ta-atom having co-ordination number 2 whereas the N-atom are present at corner and face-centre having co-ordination number is 2.

Therefore, the formula of the compound is TaC.