Advertisements
Advertisements
प्रश्न
Aluminium crystallises in a cubic close-packed structure. Its metallic radius is 125 pm.
- What is the length of the side of the unit cell?
- How many unit cells are there in 1.00 cm3 of aluminium?
Advertisements
उत्तर
i. For cubic close-packed structure:
`r = a/(2 sqrt 2)`
`a = 2 sqrt 2 r`
= `2 sqrt 2 xx 125`
= `2 xx 1.414 xx 125`
= 353.55 pm
= 353.55 × 10−10 cm
= 3.54 × 10−8 cm
ii. Volume of one unit cell = a3
= (3.54 × 10−10)3 cm3
= (44.3 × 10−24) cm3
= 4.43 × 10−23 cm3
Hence, number of unit cells in 1.00 cm3
= `1.00/(4.43 xx 10^-23)`
= `1.00/4.43 xx 10^23`
= 0.225 × 1023
= 2.25 × 1022
संबंधित प्रश्न
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?
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?
How many lattice points are there in one unit cell of the following lattice?
Face-centred cubic
A cubic solid is made of two elements P and Q. Atoms of Q are at the corners of the cube and P at the body-centre. What is the formula of the compound? What are the coordination numbers of P and Q?
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.
Hexagonal close packed arrangement of ions is described as ____________.
The arrangement ABC ABC.... is referred to as ____________.
What is the coordination number in a square close packed structure in two dimensions?
In NaCl structure ____________.
Which of the following statement is not true about the hexagonal close packing?
With the help of a labelled diagram show that there are four octahedral voids per unit cell in a cubic close packed structure.
In the SF4 molecule, there are:
The octane number of Iso-octane is
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?
Which of the following is frenkal effect.
The right option for the number of tetrahedral and octahedral voids in hexagonal primitive unit cell is ______.
Element 'B' forms ccp structures and A occupies half of the octahedral voids, while oxygen atoms occupy all the tetrahedral voids. The structure of bimetallic oxide is ______.
