Advertisements
Advertisements
प्रश्न
The density of iron crystal is 8.54-gram cm–3. If the edge length of the unit cell is 2.8 A° and atomic mass is 56 gram mol–1, find the number of atoms in the unit cell. (Given: Avogadro's number = 6.022x1023,1A° = 1x10-8 cm)
Advertisements
उत्तर
Given a = 2.8Å = `2.8 xx 10^(-8)` cm
Molar Mass = 56 gm
Density = 8.54 g cm-3
Volume = (a)3
`= (2.8 xx 10^(-8))^3`
`= 21.95 xx 10^(-24) cm^3`
Density of unit cell = `"Mass of unit cell"/"Volume of unit cell"`
∴ Mass of unit cell = density x volume
`= 21.95 xx 10^(-24) xx 8.54`
`= 187.47 xx 10^(-24)`
56 gm of Fe contains 6.022 x 1023 atoms
`187.47 xx 10^(-24)` gm Fe contain = `(6.022xx10^23 xx 187.47xx10^(-24))/56`
= `20.15xx 10^(-1)`
= 2.01
= 2
Number of atoms in unit cell is 2.
APPEARS IN
संबंधित प्रश्न
The coordination number of atoms in bcc crystal lattice is ______.
Answer the following in one or two sentences.
Sketch a tetrahedral void.
How are tetrahedral and octahedral voids formed?
Third layer of spheres is added to second layer so as to form hcp or ccp structure. What is the difference between the addition of third layer to form these hexagonal close-packed structures?
An octahedral void is surrounded by ________.
The coordination number of spheres in the hcp lattice in three dimension is ______.
The number of tetrahedral voids are formed if the number of atoms in a crystal is N/2.
The number of octahedral voids formed in 0.5 mol of a compound forming hcp structure?
In hexagonal close packed (hep) structure, ____________ layer and ____________ layer have horizontal and vertical alignment.
An element crystallises in a bee lattice with cell edge of 500 pm. The density of the element is 7.5 g cm-3. How many atoms are present in 300 g of metal?
A metallic element crystallises in simple cubic lattice. If edge length of the unit cell is 3Å, with density 8 g/cc, what is the number of unit cells in 100 g of the metal?
(Molar mass of metal = 108 g/mol)
A compound has fcc structure. If density of unit cell is 3.4 g cm−3, what is the edge length of unit cell?
(Molar mass = 98.99)
Xenon crystallises in fcc lattice and the edge length of unit cell is 620 pm. What is the radius of Xe atom?
The coordination number of each sphere in bcc lattice is ____________.
In two dimensional AAAA type packing, the coordination number of each sphere is ____________.
The atoms of element 'Y' form hexagonal close packing and the atoms of element X occupies `3/4` th portion of the number of tetrahedral voids. The formula of the compound formed by X and Y is ____________.
Which of the following has hcp crystal structure?
What is the coordination number of cation in ionic compound if the type of hole occupied by cation is octahedral?
Aluminium crystallises in a cubic close-packed structure with a unit cell edge length of 353.6 pm. What is the radius of Al atom? How many unit cells are there in 1.00 cm3 of Al?
Percentages of free space in cubic close-packed structure and in the body-centered packed structure are respectively ______.
What is the coordination number of atoms in bcc crystal lattice?
Predict the type of cubic lattice of a solid element having edge length of 400 pm and density is 6.25 g/ml.
(Atomic mass of element = 60)
Find the total number of tetrahedral and octahedral voids formed in 1 mole of a compound forming hcp structure.
If the length of the body diagonal of a FCC unit cell is xÅ, the distance between two octahedral voids in the cell in Å is ______.
Calculate the volume occupied by a particle in a simple cubic unit cell if the volume of the unit cell is 5.5 × 10−22 cm3.
