Class 12, subject chemistry chapter name solid state, topic name - calculations involving unit cell dimensions and imperfections in solids

1. Quality Education For All

2. CLASS 12
CHAPTER 1-SOLID STATE

3. RECAP
✓ Packing Efficiency
✓ hcp and ccp structures
✓ BCC structures
✓ SCC structures

4. Calculations Involving Unit Cell Dimensions
d = z.m/a3 d = z.M/a3. NA

5. Problem 1
An element has a body-centred cubic (bcc) structure
with a cell edge of 288 pm. The density of the
element is 7.2 g/cm3. How many atoms are present
in 208 g of the element?

6. Problem 1
12.08 × 1023
unit cells
24.16 × 1023
unit cells

7. Problem 2
Silver forms ccp lattice and X-ray studies of its
crystals show that the edge length of its unit cell
is 408.6 pm. Calculate the density of silver
(Atomic mass = 107.9 u).
6.82 × 107 × 10-36 m3

8. Problem 2
6.82 × 107 × 10-36 m3

9. Problem 3
A compound forms hexagonal close-packed
structure. What is the total number of
voids in 0.5 mol of it? How many of these
are tetrahedral voids?
3.011 × 1023 atoms

10. Problem 3
3.011 × 1023 atoms

11. Problem 4
An element with molar mass 2.7×10-2 kg mol-1
forms a cubic unit cell with edge length 405 pm.
If its density is 2.7×103 kgm-3, what is the
nature of the cubic unit cell?

12. Problem 4

13. Imperfections in solids
Defects
Point Defects
Line Defects

14. Point Defects
Stoichiometric Defects
Impurity Defects
Non-Stoichiometric Defects
Imperfections in solids