Advertisements
Advertisements
Question
How are tetrahedral and octahedral voids formed?
Solution
- Two dimensional hexagonal close-packed layer has triangular voids which is formed by three spheres.
- When the triangular voids of the first layer are covered by spheres of the next layer, tetrahedral voids are formed. A tetrahedral void is surrounded by four spheres.
- The overlapping triangular voids from the two layers together form an octahedral void.
An octahedral void is surrounded by six spheres. - Thus, the depressions in which spheres of second layer rest are tetrahedral voids while the depressions in which no sphere rests are octahedral voids.
APPEARS IN
RELATED QUESTIONS
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)
Choose the most correct answer.
The coordination number of atoms in bcc crystal lattice is _______.
Answer the following in one or two sentences.
Sketch a tetrahedral void.
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.
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)
Xenon crystallises in fcc lattice and the edge length of unit cell is 620 pm. What is the radius of Xe atom?
In two dimensional AAAA type packing, the coordination number of each sphere is ____________.
The coordination number of Rh in the complex [Rh(NH3)3(SCN)3] 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 ____________.
A metallic element crystallizes 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 108 g of the metal?
(Molar mass of metal = 100 g/mol)
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?
Which metal crystallises in a simple cubic structure?
Which among the following metals crystallise as a simple cube?
What is the coordination number of atoms in bcc crystal lattice?
The coordination number of cobalt in the complex [Co(en)2Br2]Cl2 is ______.
The number of octahedral sites per sphere in ccp structure is ______.
How much vacant space is present in hep 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)
