1) What is coordination no of atoms : A) IN A CUBIC CLOSE PACKED STRUCTURE b) In abcc 2) A cubic solid is made of two elements P & Q . Atoms of Q are at the corners of the cube and P at the body centre.What is formula of the compound? What are the coordination no P & Q ? 3) If the radius of octahedral void is are r and radius of the atoms in close packing is R derive relation between r & R ? 4 ) Ferric oxide crystallise in a hexagonal close packed array of oxides ions with two out of every three octahedral holes occupied by ferric ions. derive the formula of ferric oxide. 5) Gold (atomic radius = 0.144 nm) crystallise in a ff centred unit cell.what is the length of a side of the cell ? 6) ALUMINIUM CRYSTALLISE IN A CUBIC CLOSE PACKED STRUCTURE . Its metallic radius is 125 pm How many unit cells are there in 1.00 cm3 of aluminium ? 7) If NaCl is dopped with 10-3 mol % of SrCl2.what is the concentration of cation vacancies ?

CBSE Class 12-science Answered

1) What is coordination no of atoms :

A) IN A CUBIC CLOSE PACKED STRUCTURE

b) In abcc

2) A cubic solid is made of two elements P & Q . Atoms of Q are at the corners of the cube and P at the body centre.What is formula of the compound? What are the coordination no P & Q ?

3) If the radius of octahedral void is are r and radius of the atoms in close packing is R derive relation between r & R ?

4 ) Ferric oxide crystallise in a hexagonal close packed array of oxides ions with two out of every three octahedral holes occupied by ferric ions. derive the formula of ferric oxide.

5) Gold (atomic radius = 0.144 nm) crystallise in a ff centred unit cell.what is the length of a side of the cell ?

6) ALUMINIUM CRYSTALLISE IN A CUBIC CLOSE PACKED STRUCTURE . Its metallic radius is 125 pm

How many unit cells are there in 1.00 cm3 of aluminium ?

7) If NaCl is dopped with 10-3 mol % of SrCl2.what is the concentration of cation vacancies ?

Asked by pandeyknk | 29 Sep, 2014, 11:39: PM

Expert Answer

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Solution for your first query:

The hexagonal closest packed (hcp) has a coordination number of 12 and contains 2 atoms per unit cell. The face-centered cubic (fcc) or cubic closed packed has a coordination number of 12 and contains 4 atoms per unit cell. The body-centered cubic (bcc) has a coordination number of 8 and contains 2 atoms per unit cell.