Dr. H.C. Srivastava and SUMEDHA SRIVASTAVA Solutions for Chapter: Solid State, Exercise 10: QUESTIONS FROM ISC EXAMINATION PAPERS

Graphite is anisotropic with respect to conduction of electric current. Explain.

In a body-centred and face-centred arrangement of atoms of an element, what will be the numbers of atoms present in respective unit cells? Justify your answer with calculation.

A compound $\mathrm{AB}$ has a simple cubic structure and has molecular mass $99$. Its density is $3.4 \mathrm{g} {\mathrm{cm}}^{-3}$. What will be the edge length of the unit cell?

In a face centred cubic lattice, atom (A) occupies the corner positions and atom (B) occupies the face centre positions. If one atom of (B) is missing from one of the face centred points, the formula of the compound is

How many sodium ions and chloride ions are present in a unit cell of sodium chloride crystal?

Frenkel defect does not change the density of the ionic crystal whereas Schottky defect lowers the density of ionic crystal. Give a reason.

Lead sulphide has face centred cubic crystal structure. If the edge length of the unit cell of lead sulphide is $495 \mathrm{pm}$, calculate the density of the crystal (at. wt. $\mathrm{Pb}=207, \mathrm{S}=32$).

Examine the defective crystal given below and answer the question that follows:

State if the above defect is stoichiometric or non- stoichiometric. How does this defect affect the density of the crystal? Also, write the term used for this type of defect.