Introduction to Imperfections in Solids

Q.

In a unit cell atoms A B C and D are present at corners face centres bodycentre and edge centres respectively.if atoms touching one of the plane passing through two diagonally opposite edges are removed then formula of compound is

Q. Ice crystallize in hexagonal lattice having volume of unit cell as 13210*-24 cm3. If density of ice at given temperature is .92gcm-3. Then number of h2o molecules per unit cell is

Q. For a tetrahedral void the correct relation between r and R is :
Here
$r\text{is radius of the tetrahedral void}$
$R\text{is radius of the atoms in close packing}$

1. $r=0.5R$
2. $r=0.732R$
3. $r=0.225R$
4. $r=0.156R$

Q. Which of the following represents the lattice structure of $F{e}_{0.95}O$?

1. 
2. 
3. Both a. and b. are correct
4. None of these

Q. 47.What is the number of second nearest neighbour in simple cubic unit cell, body center cubic unit cell, face centered cubic unit cell.

Q. The conductivity of an intrinsic semiconductor can be increased by:

1. Heating the semiconductor
2. Doping the semiconductor with electron rich impurity
3. Doping the semiconductor with electron deficient impurity
4. Cooling the semiconductor

Q. In a simple cubic lattice of anions, the side length of the unit cell is $2.88$ $\stackrel{\circ }{A}$. The diameter of the void in the body centre is:

1. $0.461$ $\stackrel{\circ }{A}$
2. $2.108$ $\stackrel{\circ }{A}$
3. $4.908$ $\stackrel{\circ }{A}$
4. $1.284$ $\stackrel{\circ }{A}$

Q. In a ccp structure, a cube is formed by joining the centres of all the tetrahedral voids to generate a new cube. Then, the new cube would contain:

1. 1 full tetrahedral void, 1 full octahedral void
2. 1 full tetrahedral void only
3. 8 full tetrahedral voids and 1 full octahedral void
4. 1 full octahedral void only

Q. Distance between any two consecutive layers in cubic close packing is (a : edge length of cubic unit cell

Q.

Assuming complete precipitation of AgCl, calculate the sum of the molar concentration of all the ions if 2l of 2M $A{g}_{2}S{O}_4$ is mixed with 4l of 1M NaCl solution is

1. 4 M

2. 2 M

3. 3 M

4. 2.5 M

Q. No.of alternate edges in cubic cell is 4. Explain

Q.

Water has a ____________ dielectric constant.

Q.

The correct statement(s) regarding defects in solids is / are

1. Frenkel defect is usually favoured by a very small difference in the sizes of cation and anion

2. Frenkel defect is a dislocation defect

3. trapping of an electron in the lattice leads to the formation of F-center

4. Schottky defects have no effect on the physical properties of solid

Q.

Atoms of element B form a ccp lattice and those of the element A occupy 2/3rd of the tetrahedral voids, the formula of the compound is:

1. A₃B₄

2. A₂B₂

3. A₂B₃

4. A₄B₃

Q.

Q5) in a crystalline solid , anions 'C' are arranged in cubic close packing cations 'A' occupy 50%of tetrahedral voids and cations 'B' occupy 50% of octahedral voids .what is the formula of the solid

Q. Discuss tetrahedral and octahedral interstitial voids in a close packed arrangement

Q. what is edge centered unit cell is it same as face centered unit cell

Q. Which of the following represents the lattice structure of $F{e}_{0.95}O$?

1. 
2. Both a. and b. are correct
3. None of these
4. 

Q. If the secondary valency in $CoC{l}_3.4N{H}_3$ is six, the solution conductivity in silver nitrate corresponds to ______ electrolyte.

1. 1:1
2. 1:2
3. 1:3
4. 1:4

Q. Which of the following statement is correct reagarding electrical conductivity of a semiconductor:

1. Decreases with the rise in temperature
2. Increases with the rise in temperature
3. Does not change with the rise in its temperature
4. First increases and then decreases with the rise in its temperature

Q. Which of the following statements is true about the hexagonal close packing in 3-D?

1. Third layer is covering the octahedral voids of second layer
2. First layer is identical to the third layer
3. Second layer occupies 25% of the voids of first layer
4. Spheres of the fourth layer are exactly aligned with those of the first layers arrangement,

Q. Octahedral voids has 6 spheres but why we call it as octahedral.?

Q.

In a solid lattice, cation and an anion both have left lattice site. The lattice defect is known as

1. valency defect

2. Frenkel defect

3. Schottky defect

4. intertial defect

Q.

Q4*) A compound?is formed by two elements M&N the element N forms CCP and atoms of M occupy 1/3rd of tetrahedral voids what is the formula of the compound

Q.

Why is cu+2 is more stable than cu+ even after its d9 orbital

Q.

What properties of magnetic substances can be explained on the basis of molecular theory?

Q.

When to write silver an when to write argentate in a coordinate compound which contains the silver metal.?

Q. The aqueous solution of $T{i}^{4+}$ ion is

1. Colourless
2. Pink in colour
3. Blue in colour
4. Violet in colour

Q. Explain why $C{u}^{+}$ ion is not stable in aqueous solutions?

Q. what is the difference between stoichiometric defect and non stoichiometric defects?