Crystalline and Amorphous Solid

Q.

Classify the following as amorphous or crystalline solids: Polyurethane, Naphthalene, Benzoic acid, Teflon, Potassium nitrate, Cellophane, Polyvinyl Chloride, Fiberglass, and Copper?

Q.

Classify the following solids in different categories based on the nature of intermolecular forces operating in them:

Potassium sulphate, tin, benzene, urea, ammonia, water, zinc sulphide, graphite, rubidium, argon, and silicon carbide.

Q.

Give 10 examples of amorphous solids and crystalline solids.

Q.

Define:-

1. Anisotropic

2. Isotropic

Q.

A compound is formed by two elements X and Y. Atoms of the element Y (as anions) make ccp and those of element X (as cations) occupy all the octahedral voids the formula for the compound is:

1. X₂Y

2. XY

3. X₂Y₂

4. XY₂

Q.

A compound is formed by elements A and B This crystallizes in the cubic

structure when atoms A are the corners of the cube and atoms B are at the

centre of the body. The simplest formula of the compounds is

[KCET 1993; CBSE PMT 2000; Kerala PMT 2002]

1. 
   

2. AB

3. 
   

4. 
   

Q. The vacant space in the bcc unit cell is

1. 26%
2. 67%
3. 32%
4. 23%

Q. In a cubic packed structure of mixed oxides, the lattice is made up of oxide ions, one fifth of tetrahedral voids are occupied by divalent $X^{2+}$ ions, while one-half of the octahedral voids are occupied by trivalent ions $Y^{3+}$, then the formula of the oxide is:

1. $X_{2}Y{O}_4$
2. $X_5{Y}_4{O}_{10}$
3. $X{Y}_2{O}_4$
4. $X_4{Y}_5{O}_{10}$

Q.

What makes a glass different from a solid such as quartz ? Under what condition could quartz be converted into glass ?

Q.

Write formulas for Epsoms salt.

Q.

The sharp melting point of crystalline solids is due to _________.

1. a regular arrangement of constituent particles observed over a short distance in the crystal lattice

2. a regular arrangement of constituent particles observed over a long distance in the crystal lattice

3. the same arrangement of constituent particles in a different direction

4. different arrangement of constituent particles in different directions

Q. In chromium (III) chloride, $\left(CrC{l}_3\right)$, chloride ions have cubic close packed arrangement and $Cr\left(III\right)$ ions are present in octahedral voids.
Choose the correct option:

1. $\text{Fraction of octahedral voids occupied}=\frac{1}{2}$
2. $\text{Fraction of total voids occupied}=\frac{1}{6}$
3. $\text{Fraction of octahedral voids occupied}=\frac{1}{3}$
4. $\text{Fraction of total voids occupied}=\frac{1}{8}$

Q.

Refractive index of a solid is observed to have the same value along all directions. Comment on the nature of this solid. Would it show cleavage property?

Q. Lattice energy of an ionic compounds depends upon:

1. Charge on the ion and size of the ion
2. Packing of ions only
3. Size of the ion only
4. Charge on the ion only

Q.

Amorphous solids can also be called ..............

(a) Pseudo solids (b) true solids

(c) super cooled liquids (d) super cooled solids

Q.

Why is glass considered a super cooled liquid?

Q. Which of the following is not a characteristic of a crystalline solid?

1. Definite and characteristic heat of fusion.
2. Isotropic nature.
3. A true solid
4. A regular periodically repeated pattern of arrangement of constituentparticles in the entire crystal.

Q. 33.NO2 is a positive ligand or negative ligands

Q.

What are the two types of solids?

Q. The density of $Ca{F}_2$(fluorite structure) is $3.18{\text{g/cm}}^3$. The length of the side of the unit cell (in pm) is:
(Given: $N_A=6\times {10}^{23},\sqrt[3]{3163.5}=5.468$)

Q. The arrangement ABC . . . ABC . . . ABC . . . is referred as

1. octahedral close packing
2. Tetragonal close packing
3. Cubic close packing
4. Hexagonal close packing

Q.

A solid is made of two elements P&Q. Atoms P are in ccp arrangement and atoms Q occupy all the octahedral voids and half of the tetrahedral voids, then the simplest formula of the compound is

1. PQ₂

2. P₂Q

3. PQ

4. P₂Q₂

Q. In a crystalline solid atom ‘a’ ccp arranged ‘b’ atom occupied octahedral voids and ‘c’ atom occupied tetrahedral voids. What will be the formula of crystalline solid if a pair of opposite face are removed?

Q.

1. Define the term 'amorphous'. Give a few examples of amorphous solids.

Q. Tungsten has a body centered cubic lattice and each lattice point is occupied by one atom. Calculate the radius of metallic tungsten if density of tungsten is 19.30 gcm^-3 and atomic weight is 183.9.

Q.

The three dimensional graph of lattice points which sets the pattern for the whole lattice is called

1. Space lattice

2. Simple lattice

3. Unit cell

4. Crystal lattice

Q. Potassium crystallizes in a body centered lattice how many unit cells are present in 2g potassium ?? Why we divide it by 2 in last? It belongs to body centered lattice and a particle at the body centre of a unit cell belongs only to the particular unit cell hence 1atom should be equal to 1 unit cell?

Q. When atoms are placed at all 12 edges of cube how many atoms are present per unit cell?

Q. In a compound $P{Q}_2{O}_4,$ oxide ions are arranged in ccp and cations P are present in octahedral voids. Cations Q are equally distributed among octahedral and tetrahedral voids. The fraction of the octahedral voids occupied is

1. 1/4
2. 1/2
3. 1/3
4. 2/3

Q. Identify R configuration:

1. 
2. 
3. 
4.