Derive the formula of the ferric oxide

Asked by Saransekar407 | 11th Mar, 2019, 06:47: PM

Expert Answer:

Question: 

Ferric oxide crystallizes in a hexagonal close-packed array of oxide ions with two out of every three octahedral holes occupied by ferric ions. Derive the formula of the ferric oxide.

 
Answer:
 
A unit cell of hcp structure = 6

No. of oxide ions per unit cell = 6

No. of octahedral voids = 6 Since, ferric ions occupy only two out of every three octahedral voids,

Therefore, no. of octahedral holes occupied by ferric ions = 2 over 3 cross times 6 space equals space 4

Stoichiometric ratio of Fe : O = 4:6 = 2:3 Hence, formula of ferric oxide = Fe2O3.

Answered by Ramandeep | 11th Mar, 2019, 07:24: PM