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प्रश्न
What is meant by the term ‘coordination number’?
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उत्तर
The number of nearest neighbours with which a given particle is in direct contact in a crystal is called the coordination number.
संबंधित प्रश्न
Describe triclinic crystal lattice with the help of a diagram.
Define the following term: Primitive unit cells
Which of the following lattices has the highest packing efficiency (i) simple cubic (ii) body-centred cubic and (iii) hexagonal close-packed lattice?
An ionic crystal lattice has limiting value of radius ratio as 0.414 to 0.732; the co-ordination number of its cation is _______.
(A) 6
(B) 4
(C) 3
(D) 12
Which of the following parameters are correct for triclinic lattice?
(A) α = β = γ = 90° and a = b = c
(B) α ≠ β ≠ γ = 90° and a ≠ b ≠ c
(C) α = γ = 90°, β ≠ 90° and a ≠ b ≠ c
(D) α ≠ β ≠ γ ≠ 90° and a ≠ b ≠ c
Calculate the number of atoms present in 2 gram of crystal which has face-centred cubic
(FCC) crystal lattice having edge length of 100 pm and density 10 gcm−3
In the complexes `[Fe(CN)_6]^(3-)` and `[pt(en) (H_2O)_2(NO_2 (Cl)^(2+)]``the respective oxidation numbers of central metal atoms are
1) +3 and +4
2) +6 and + 4
3) +6 and +3
4) +3 and + 3
i)
Consider the following cell reaction at 298 K: [3]
2Ag+ + Cd → 2Ag + Cd2+
The standard reduction potentials (E°) for Ag+/Ag and Cd2-/Cd are 0.80 V and -0.40 V respectively:
(1) Write the cell representation.
(2) What will be the emf of the cell if the concentration of Cd2+ is 0.1M and that of Ag+ is 0.2 M?
(3) Will the cell work spontaneously for the condition given in (2) above?
(ii)
What is a buffer solution? How is it prepared? Explain the buffer action of a basic buffer with a suitable example.
Complete the following statement by selecting the correct alternative from the choices given:
In a face-centered cubic lattice, atom (A) occupies the comer positions and atom (B) occupies the face centre positions. If one atom of (B) is missing from one of the face-centered points, the formula of the compound is:
In a crystal of diamond:
- How many carbon atoms are present per unit cell?
- What type of lattice does diamond crystallise in?
- How many carbon atoms surround each carbon atom?
- How are they arranged?
A solid compound XY has NaCl structure. if the radius of the cation is 100 pm, the radius of the anion will be
The yellow colour in NaCl crystal is due to ____________.
Why ionic crystals are hard and brittle?
How many three-dimensional crystal lattices are possible?
A particular solid is very hard and has a high melting point. In solid state, it is a non-conductor and in molten state, it is a conductor of electricity. Classify the solid ______.
How many unit cells are present in a cube-shaped ideal crystal of NaCl of mass 1.00 g? [Atomic masses: Na = 23, Cl = 35.5]
