Advertisements
Advertisements
Question
How many lattice points are there in one unit cell of each of the following lattice?
(i) Face-centred cubic
(ii) Face-centred tetragonal
(iii) Body-centred
Solution
(i) There are 14 (8 from the corners + 6 from the faces) lattice points in face-centred cubic.
(ii) There are 14 (8 from the corners + 6 from the faces) lattice points in face-centred tetragonal.
(iii) There are 9 (1 from the centre + 8 from the corners) lattice points in body-centred cubic
APPEARS IN
RELATED QUESTIONS
A compound is formed by two elements M and N. The element N forms ccp and atoms of M occupy 1/3rdof tetrahedral voids. What is the formula of the compound?
Ferric oxide crystallises 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.
Aluminium crystallises in a cubic close-packed structure. Its metallic radius is 125 pm.
(i) What is the length of the side of the unit cell?
(ii) How many unit cells are there in 1.00 cm3 of aluminium?
The coordination number of AB having rock salt geometry is ____________.
What is the coordination number in a square close packed structure in two dimensions?
Which of the following statement is not true about the hexagonal close packing?
Match the type of packing given in Column I with the items given in Column II.
Column I | Column II |
(i) Square close packing in two dimensions |
(a) Triangular voids |
(ii) Hexagonal close packing in two dimensions |
(b) Pattern of spheres is repeated in every fourth layer |
(iii) Hexagonal close packing in three dimensions |
(c) Coordination number 4 |
(iv) Cubic close packing in three dimensions |
(d) Pattern of sphere is repeated in alternate layers |
With the help of a labelled diagram show that there are four octahedral voids per unit cell in a cubic close packed structure.
How can you best describe the elongated octahedral structure of blue vitriol, CuSO4.5H2O?
In the SF4 molecule, there are:
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?
The number of tetrahedral and octahedral voids in a CCP array of 100 atoms are respectively:
The right option for the number of tetrahedral and octahedral voids in the hexagonal primitive unit cell is _______.
The right options for the number of tetrahedral and octahedral voids in the hexagonal primitive unit cells is ______.
Ionic radii of cation A+ and anion B- are 102 and 181 pm respectively. These ions are allowed to crystallize into an ionic solid. This crystal has cubic close packing for B-. A+ is present in all octahedral voids. The edge length of the unit cell of the crystal AB is ______ pm. (Nearest integer)
The empirical formula for a compound with a cubic close packed arrangement of anions and with cations occupying all the octahedral sites in AxB. The value of x is ______. (Integer answer)
The density of a pure substance 'X' whose atoms pack in cubic close pack arrangement is 1 g/cc. If all tetrahedral voids are occupied by 'Y' atoms. The value of '3a' is ______ g/cc, if the density of resulting solid is 'a' g/cc.
[Given: Atomic mass (X) = 30 g/mol, (Y) = 20 g/mol]