SOLID STATE ASSIGNMENT SUBJECTIVE

1.	Why are amorphous solids is isotropic is nature?
2.	ASSIGNMENT :- SOLID STATE         Submittion latest by 12-4-13   How many spheres are in contact with each other in a single plane of a close packed structure?
3.	A solid ‘X’ conducts electricity in solid state as well as in molten state. Its conductance decreases with increase in temperature. Identify the solid X.
4.	What is the coordination number of an octahedral void
5.	Arrange the following types of interactions in correct order of their increasing strength :             Covalent, hydrogen bonding, Vander Waals, dipole dipole
6.	Why is quartz regarded as a crystalline solid while glass an amorphous solid
7.	Metallic gold crystallizes in FCC lattice. How many nearest neighbours do each gold atom has?
8.	Identify the crystal systems which have the following crystallographic dimensions:
9.	In BCC lattice, what are the numbers of the nearest and next nearest neighbours?
10.	Explain how much portion of an atom located at (a) corner (b) body centre and (c) face-centre of a cubic unit cell in part of its neighbouring unit-cell
11.	compound forms hexagonal close packed structure. What is the total number of voids in 0.5 mol of it? How many of these are tetrahedral voids?
12.	In the face centered cubic arrangement of A and B atoms where A atoms are at the corner of the unit cell and B atoms at the face centres. One of the A atom is missing from one corner in the unit cell. What is the simplest formula of the compound?
13.	(ii) What is the (a) percentage of free space and (b) coordination number of a sphere in the  following close packed structure. (A) Hexaginal close pack.     (B) Body centred close pack.
14.	Gold (atomic radius = 0.144 nm) crystallises in a face centred unit cell. Calculated the length of a side of the cell.
15.	Aluminium crystallises in a cubic close packed structure. Its metallic radius is 125 pm. (i) What is the length of the side of the unit cell? (ii) How many unit cell are there in 1.00 cm3 of aluminium?
16.	A compound formed by elements P and Q crystallises in cubic structure where P atom are at the corners of a cube and Q atoms are at the face centre. What is the formula of the compound?
17.	A fcc element (molar, mass = 60 g mol–1 has cell edge 4.0 × 10–8 cm. Calculate its density (NA= 6.023 × 1023 mol–1).
18.	A compound AB crystallizes in BCC lattice with unit cell edge length of 480Pm. If the radius of B is 225Pm. Calculate the radius of A+.
19.	An element crystallises in a structure having a fcc unit cell of an edge 200 pm. calculate its density if 200 g of this element contain 24 × 1023 atoms. [Ans. : 41.6 g cm–3]
20.	In Chromium(III) Chloride, CrCl3, chloride ions have cubic close packed arrangement and Cr(III) ions are present in the octahedral holes. What is the fraction of octahedral holes occupied? What is the fraction of total number of holes occupied?
21.	A metallic element has a body central cubic lattice. Each end of its unit cell is 2.88 × 10–8 cm. The density of the metal is 7.20 g cm–3. Calculate : (i) The volume of unit cell. (ii) Mass of unit cell. (iii) Number of atoms in 100 g of metal
22.	Niobium crystallises in body-centred cubic structure. Its density is 8.55 g cm–3. Calculate atomic radius of niobium using is atomic mass 93u. (NA = 6.022 × 1023 mol–1).
23.	In the normal spinel structure, the oxide ions are arranged in CCP pattern. The Zn2+ ions occupy one eighth of the tetrahedral holes and one half of the octahedral voids areoccupied by Al3+. Give the formula of the spinel.