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प्रश्न
How will you distinguish between the following pair of terms?
Crystal lattice and unit cell
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उत्तर
| Crystal lattice | Unit cell |
| The three-dimensional arrangement of structural units or constituent particles (atoms, molecules or ions) in a crystal is called a space lattice or crystal lattice or simply a lattice. | Unit cell is the smallest three-dimensional group of lattice points which, when repeated in three dimensions in space, gives the whole lattice of the crystal. |
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संबंधित प्रश्न
Define the following term: Primitive unit cells
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
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
An ionic crystal lattice has `r^+/r` radius ratio of 0.320, its coordination number is __
(a) 3
(b) 4
(c) 6
(d) 8
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.
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?
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]
