Solid state practice · Mixed difficulty

Under which category iodine crystals are placed among the following?

The limiting radius ratio for tetrahedral shape is

Which is not the correct statement for ionic solids in which positive and negative ions are held by strong electrostatic attractive forces?

8:8 co-ordination of $\mathrm{CsCl}$ is found to change into 6:6 co-ordination on :

If the distance between ${Na}^{+}$and ${Cl}^{-}$ions in sodium chloride crystal is $y$ pm, the length of the edge of the ${c}$ unit cell is

The coordination number of Al in the crystalline state of $\mathrm{AlC}{\mathrm{l}_3}$ is

In a crystal of $\mathrm{NaCl}$, if all the ions along one of the body diagonal are removed then the simplest formula of the crystalline solid will be

The structure of $\mathrm{MgO}$ is similar to $\mathrm{NaCl}$. The co-ordination number of $\mathrm{Mg}$ is :

Which is the incorrect statement

If ‘a’ stands for the edge length of the cubic systems: Simple, Cubic, body centred cubic face centred cubic, then the ratio of radii of the spheres in these systems will be respectively.

In a face centred cubic arrangement off $A$ and $B$ atoms whose 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 unit cell. The simplest formula of compound is :

In calcium fluoride, having the fluorite structure, the coordination numbers for calcium ion $(C{a^{2 + }})$ and fluoride ion $({F^ - })$ are

A crystal is made up of metal ions ${M_1}$ and ${M_2}$ and oxide ions. Oxide ions form a ccp lattice structure. The cation ${M_1}$ occupies 50 % of octahedral voids and the cation ${M_2}$ occupies 12.5% of tetrahedral voids of oxide lattice. The oxidation numbers of ${M_1}$ and ${M_2}$ are, respectively

Which of the following statements is not correct?

Statement I: Hexagonal closest-packed structure and a cubic closest-packed structure for a given element would be expected to have the same density.

Statement II: The two structures have the same (CN), hence the same packing fraction (density).

A crystalline solid

The solid is a bad conductor of electricity since

Ferrous oxide has a cubic structure and each edge of the unit cell is $5.0$. Assuming density of the oxide as $4.0g/c{m^{ - 3}}$ then the number of $\mathrm{F}{\mathrm{e}^{2 + }}$ and ${\mathrm{O}^{2 - }}$ ions present in each unit cell will be

Frenkel defect is found in crystals in which the radius ration is

If the positions of $\mathrm{N}{\mathrm{a}^ + }$ and $\mathrm{C}{\mathrm{l}^ - }$ are interchanges in NaCl, the crystal lattice with respect to $\mathrm{N}{\mathrm{a}^ + }$ and $\mathrm{C}{\mathrm{l}^ - }$ is :

Which of the following is not a correct combination:

The edge length of unit cell of a metal having molecular weight $75 \mathrm{~g} / \mathrm{mol}$ is $5\mathop {\text{A}}\limits^ \circ$ which crystallizes in cubic lattice. If the density is $2 \mathrm{~g} /$ $\mathrm{cc}$ and the radius of metal atom is $4.33 \mathrm{xpm} .\left(\mathrm{N}_{\mathrm{A}}\right.$ $=6 \times 10^{23}$ ). Find the value of $x$.

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : In a particular point defect, an ionic solid is electrically neutral, even if few of its cations are missing from its unit cells.
Reason (R) : In an ionic solid, Frenkel defect arises due to dislocation of cation from its lattice site to interstitial site, maintaining overall electrical neutrality.
In the light of the above statements, choose the most appropriate answer from the options given below

Which defect causes decreases in the density of crystal?

The constituent particles of a solid have

Certain crystals produces electric signals on application of pressure. This phenomena is called

Which crystal is expected to be soft and have low melting point?

Edge length of a cube is 400 pm. Its body diagonal would be :

At room temperature, sodium crystallizes in a body centered cubic lattice with $a = 4.24\mathop \mathrm{A}\limits^ \circ$. the theoretical density of sodium $\mathrm{(At}\mathrm{. wt}\mathrm{. Of\; Na} = 23)$ is :

Which of the following expressions is correct in case of a $\mathrm{CsCl}$ unit cell (edge length ' $a$ ')?