Advertisements
Advertisements
प्रश्न
The lattice site in a pure crystal cannot be occupied by ______.
पर्याय
molecule
ion
electron
atom
Advertisements
उत्तर
The lattice site in a pure crystal cannot be occupied by electron.
Explanation:
Pure crystals have constituents i.e., atoms or molecules or ions as lattice points which are arranged in fixed stoichiometric ratio. Electron can occupy the lattice site only when there is imperfection in solid and not in a pure crystal.
Hence, existence of free electrons are not possible, it is possible on in case of imperfection in solid.
APPEARS IN
संबंधित प्रश्न
How will you distinguish between the following pair of terms?
Crystal lattice and unit cell
Give the significance of a ‘lattice point’.
Name the parameters that characterize a unit cell.
Which of the following lattices has the highest packing efficiency (i) simple cubic (ii) body-centred cubic and (iii) hexagonal close-packed lattice?
What is meant by the term ‘coordination number’?
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
An ionic crystal lattice has `r^+/r` radius ratio of 0.320, its coordination number is __
(a) 3
(b) 4
(c) 6
(d) 8
For a crystal of sodium chloride, state the type of lattice in which it crystallises.
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.
How will you obtain pure potassium permanganate (KMnO4) crystals from its ore, pyrolusite? Give the steps involved and the reactions.
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 ____________.
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 ______.
