Solid State Exercise - I

University:
Minnesota State University Moorhead
Course:
CHEM-150 | General Chemistry I
Academic year:

2022
Views:

475

Pages:

1
Author:

Vivian Bernard

Page # 22 SOLID STATE EXERCISE – I UNSOLVED PROBLEMS Q.1 (i) What is meant by the term coordination number? (ii) What is the coordination number of atoms: (a) in a cubic close - packed structure? (b) in a body-centred cubic structure? Q.2 How will you distinguish between the following pairs of terms: (i) Hexagonal close -packing and cubic close -packing? (ii) crystal lattice and unit cell? (iii) Tetrahedral void and octahedral void? Q.3 How many lattice points are there in one unit cell of each of the following lattice? (i) Face-centred cubic (ii) Face-centred tetragonal (iii) Body-centred Q.4 Calculate the efficiency of packing in case of a metal crystal for (i) simple cubic (ii) body-centred cubic (iii) face-centred cubic (with the assumptions that atoms are touching each other). Q.5 A cubic solid is made of two elements P and Q. Atoms of Q are at the corners of the cube and P at the body-centre. What is the formula of the compound? What are the coordination numbers of P and Q? Q.6 Analysis shows that nickel oxide has the formula NiO98O1.00. What fractions of nickel exist as Ni2+ and Ni3+ ions ? Q.7 Ferric oxide crystallises in a hexagonal close-packed array of oxide ions with two out of every three octahedral holes occupied by ferric ions. Derive the formula of the ferric oxide. Q.8 Gold (atomic radius = 0.144 nm) crystallises in a face -centred unit cell. What is the length of a side of the cell? Q.9 In terms of band theory, what is the difference between (i) a conductor and an insulator (ii)a conductor and semiconductor? Q.10 Explain the following terms with suitable examples: (i) Schottky defect (ii) Frenkel defect (iii) Intersititials and (iv) F-centres Q.11 Explain the following with suitable examples (i) Ferromagnetism (ii) Paramagnetism (iii) Ferrimagnetism (iv) Antiferromagnetism (v) 12-16 and 13-15 group compounds.