Solid state practice · Mixed difficulty

Which of the following statements is not correct?

Assertion (A) Both Frenkel and Schottky defects are stoichiometric defects.

Reason (R) Both defects change the density of the crystalline solid.

In a cubic crystal, $\mathrm{A}$ atom placed at every corners and $\mathrm{B}$ atom placed at every centre of face. The formula of compound is

For orthorhombic system axial ratios are $a \ne b \ne c$ and the axial angles are

Which of the following point defects are shown by Ag Br (s) crystals

i) Schottky defect ii) Frenkel defect

iii) Metal excess defect iv) Metal deficiency defect

In antifluorite structure, the negative ions:

Consider the bcc unit cells of the solids 1 and 2 with the position of atoms as shown below. The radius of atom $B$ is twice that of atom $A.$ The unit cell edge length is 50% more is solid 2 than in 1. What is the approximate packing efficiency in solid 2?

Which type of solid crystals will conduct heat and electricity?

The correct statement regarding F-centre is

Which of the following statement is true?

Which defect may be present in $NaCl$ crystal?

Experimentally it was found that a metal oxide has formula ${M_{0.98}}O.$ Metal $M$, present as ${M^{2 + }}$ and ${M^{3 + }}$ in its oxide. Fraction of the metal which exists as ${M^{3 + }}$ would be

The edge of unit cell of fcc Xe crystal is 620 pm. The radius of Xe atom is

Density of a crystal remains unchanged as a result of

Sodium metal crystallizes in a body centred cubic lattice with the cell edge ${\mathrm{a = }4.29\mathop \mathrm{A}\limits^ \circ }$. The radius of sodium atom is :

The melting point of $\mathrm{RbBr}$ is $\mathrm{682}^\circ \mathrm{C}$, while that of $\mathrm{NaF}$ is $\mathrm{988}^\circ \mathrm{C}$. The principle reason that melting point of $\mathrm{NaF}$ is much higher than that of $\mathrm{RbBr}$ is that :

Potassium crystallizes in a bcc lattice, hence the coordination number of potassium metal is

A solid $X$ melts slightly above $273\;K$ and is a poor conductor of heat and electricity. To which of the following categories does it belong?

An atom forms face centered cubic crystal with density $d=8.92 \mathrm{~g} / \mathrm{mL}$ and edge length $a=3.6 \times 10^{-8} \mathrm{~cm}$. The molecular mass of atom in amu is

If the value of ionic radius ratio $\left( {\frac{{{r_c}}}{{{r_a}}}} \right)$ is 0.52 in an ionic compound, the geometrical arrangement of ions in crystal is

Which is the wrong statement regarding a crystal containing Schottky defect?

In the fluorite structure, the coordination number of $C{a^{2 + }}$ ion is

Potassium fluoride has $NaCl$ type structure. What is the distance between ${K^ + }$ and ${F^ - }$ ions if cell edge is $a$ cm?

Which one of the following metal oxides is antiferromagnetic in nature?

Which of crystal systems contains the maximum number of Bravais lattices?

Statement I: Amorphous $\mathrm{B}_2 \mathrm{O}_3$ could be considered in the form of a liquid even thougn it looks like a solid, is rigid and shatters when struck with a hammer.

Statement II: $\mathrm {B -O}$ arrangement is random and $\mathrm{B}_2 \mathrm{O}_3$ is not crystalline.

The crystal are bounded by plane faces $(f)$, straight edges $(e)$ and interfacial angel $(c)$. The relationship between these is :

In a crystal, the atoms are located at the position of ……….potential energy.

$\mathrm{CsBr}$ crystal has bcc structure. It has an edge length of 4.3 Å. The shortest interionic distance between $\mathrm{C}{\mathrm{s}^ + }$ and $\mathrm{B}{\mathrm{r}^ - }$ ions is

Packing efficiency of fcc lattice is