Q1. Why is there no decrease in density during Frenkel defect in a crystal ?
Q2. Name the compound in which Schottky and Frenkel defect are present together.
Q3. Why CdCl2 added to AgI increases conduction of AgI ?
Q4. What type of compounds show Schottky defect ?
Q5. Mention one property which is caused due to the presence of F-centres in a solid.
Q6. What is the effect of presence of Schottky and Frenkel defects on the neutrality of a crystalline solid ?
Q7. What type of crystal defect is produced when sodium chloride is doped with MgCl2 ?
Q8. What type of defect is produced when NaCl is doped with AlCl3, assuming AlCl3 to be an ionic compound ?
Q9. Classify the following solids on the basis of bonding consideration : CO2, MgO, Al, H2, Si, Si, Ga, Pb, AgCl.
Q10. What is the coordination number of each type of ions in a rock salt type crystal structure ?
Q11. What is the two dimensional coordination number of a molecule in square close-packed layer ?
Q12. Why is potassium chloride sometimes violet instead of pure white ?
Q13. Name an element with which silicon may be doped to give a p-type semiconductor.
Q14. What happens to a NaCl type of structure when high pressure is applied on ?
Q15. What is meant by transition temperature ?
Q16. What happens when ferromagnetic Fe3O4 is heated at 850K ?
Q17.AgI crystallizes in a cubic close packed ZnS structure.What fraction of tetrahedral sites is occupied by Ag+ ions ?
Q18. What is the C.N. of octahedral void ?
Q19. What is the formula of the crystalline compound in which of the atoms A are present at all the eight corners and
atoms B at the centers of all the six faces ?
Q20. A metallic element crystallizes into a lattice containing sequence of layers AB AB AB ……. Any packing
of spheres leaves out voids in the lattice. What percentage by volume of this lattice is empty space ?