iCON Education - Solid State TS-EAMCET Test

A metal ( $M$ ), crystallises in fcc lattice with edge length of $4.242 \mathop {\rm{A}}\limits^{\rm{o}}$. What is the radius of $M$ atom (in $\mathop {\rm{A}}\limits^{\rm{o}}$ )?

Sodium metal crystallises in a body centred cubic lattice with edge length of $x \mathop {\rm{A}}\limits^{\rm{o}}$. If the radius of sodium atom is $1.86 \mathop {\rm{A}}\limits^{\rm{o}}$ the value of $x$ is

3.93

$\mathop {\rm{A}}\limits^{\rm{o}} $

The incorrect statement about crystals with schottky defect is

it is due to missing of equal number of cations and anions from lattice points.

on the whole crystal is electrically neutral.

it is shown by ionic compounds in which cation and anion are of almost same size.

density of the crystal increases.

A metal crystallises in two cubic phases, fcc and bcc with edge lengths $3.5 \mathop {\rm{A}}\limits^{\rm{o}}$ and $3 \mathop {\rm{A}}\limits^{\rm{o}}$ respectively. The ratio of densities of fcc and bcc is approximately

A solid contains elements $A$ and $B$. Anions of $B$ form ccp lattice. Cations of $A$ occupy 50\% of octahedral voids and 50\% of tetrahedral voids. What is the molecular formula of the solid?

A substance has a density of $2 \mathrm{~g} \mathrm{~cm}^{-3}$. It crystallises in the fcc crystal with an edge length of 600 pm . The molar mass of the substance (in $\mathrm{g} \mathrm{mol}^{-1}$ ) is $\left(N_A=6 \times 10^{23} \mathrm{~mol}^{-1}\right)$

In bcc lattice containing $X$ and $Y$ type of atoms, $X$ type of atoms are present at the corners and $Y$ type of atoms are present at the centers. In its unit cell, if three atoms are missing in the corners, the formula of the compound is

The molecular formula of a crystal is $A B_{2} \mathrm{O}_{4}$. Oxygen atoms form ccp lattice. Atoms of $A$ occupy $x \%$ of tetrahedral voids and atoms of $B$ occupy $y \%$ of octahedral voids. $x$ and $y$ are respectively

An element with molar mass $2.7 \times 10^{-2} \mathrm{~kg} \mathrm{~mol}^{-1}$ forms a cubic unit cell with edge length of 405 pm . If its density is $2.7 \times 10^3 \mathrm{~kg} \mathrm{~m}^{-3}$, the number of atoms present in one unit cell of it is (Given; $N_A=6.023 \times 10^{23} \mathrm{~mol}^{-1}$ )

Identify the correct statement about the crystal defects in solids.

Frenkel defect is favoured when the difference between sizes of cation and anion is very small.

Frenkel defect is not a dislocation effect.

Schotthy defects have no effect on physical properties of solids.

Trapping of electrons in lattice leads to the formation of F-centres.

The molecular formula of a compound is $A B_2 \mathrm{O}_4$. Atoms of $O$ form ccp lattice. Atoms of $A$ (cation) occupy $\frac{1}{8}$ th of tetrahedral voids. Atoms of $B$ (cation) occupy a fraction of octahedral voids. What is the fraction of vacant octahedral voids?

In the structure of a solid, W atoms are located at the cube corners of the unit cell, O atoms are located at the cube edges and Na atoms at the cube centres. The formula of the compound is

$\mathrm{Na}_2 \mathrm{~W}_2 \mathrm{O}_2$

$\mathrm{Na}_2 \mathrm{WO}_3$

The formula of a metal oxide is $M_{0.96} \mathrm{O}_1$. The fractions of metal that exists as $M^{3+}$ and $M^{2+}$ ions in that oxide are respectively

A compound is formed by elements $A, B$ and O . Atoms of oxygen form ccp lattice. Atoms of $A$ (cation) occupy $\frac{1}{8}$ th of tetrahedral voids and atoms of $B$ (cation) occupy half of octahedral voids. What is the molecular formula of the compound?

$\mathrm{A}_2 \mathrm{BO}_4$

$\mathrm{AB}_2 \mathrm{O}_4$

A body centred cubic lattice is made up of two different types of atoms $X$ and $Y$. Atom $X$ occupies the body centre and atoms $Y$ occupy the corner positions. One of the corners is left unoccupied per unit cell. The empirical formula of it is

Identify the crystal system in which primitive unit cell has edge lengths $a=b=200 \mathrm{pm}$ and $c=300 \mathrm{pm}$ and all axial angles are same

Assertion (A) Graphite is used as a dry lubricant in machines which run at high temperatures.

Reason ( $\mathbf{R}$ ) The layers of graphite slip one over the other when pressure is applied.

The correct option among the following is

(A) is true but (R) is false

(A) is false but $(R)$ is true

$(A)$ and $(R)$ are true and $(R)$ is the correct explanation of $(A)$

(A) and (R) are true, but $(R)$ is not the correct explanation of $(A)$

At $T(\mathrm{~K})$, copper (atomic mass $=63.5 \mathrm{u}$ ) has fce structure with an edge length of $x \AA$. The density of copper (in $\mathrm{g} \mathrm{cm}^{-3}$ ) at that temperature approximately is $\left(N_A=6.0 \times 10^{23} \mathrm{~mol}^{-1}\right)$

A solid has a structure in which ' W ' atoms are located at the corners of a cubic lattice, oxygen atoms at the edge centre and

Na atom at the body centre. The formula of the compound is

$\mathrm{Na}_2 \mathrm{WO}_3$

KBr has rock salt type structural arrangements and has a density of

$3.70 \mathrm{~g} / \mathrm{cm}^3$. The edge length of the unit cell is approximately [molecular weight of $\mathrm{KBr}=120 \mathrm{~g} / \mathrm{mol}$ ]

$3 \times 10^{-8} \mathrm{~cm}$

$12 \times 10^{-8} \mathrm{~cm}$

$9 \times 10^{-8} \mathrm{~cm}$

$6 \times 10^{-8} \mathrm{~cm}$

If the length of the body diagonal of a FCC unit cell is $x \mathop {\rm{A}}\limits^{\rm{o}}$, the distance between two octahedral voids in the cell in $\mathop {\rm{A}}\limits^{\rm{o}}$ is

$\frac{x}{\sqrt{2}}$

$\frac{x}{\sqrt{3}}$

$\frac{x}{\sqrt{6}}$

$\frac{x}{\sqrt{8}}$

The number of nearest neighbours in a bcc unit cell is

The correct option for axial distances and axial angles for hexagonal crystal system is

$a \neq b \neq c, \alpha \neq \beta \neq \gamma=90^{\circ}$

$a=b \neq c, \alpha=\beta=\gamma=90^{\circ}$

$a=b \neq c, \alpha=\beta=90^{\circ}, \gamma=120^{\circ}$

$a \neq b \neq c, \alpha=\beta=\gamma=90^{\circ}$

Iron crystalises in FCC with an edge length of 400 pm . If it contains $0.1 \%$ Schottky defects, calculate its approximate density

[Atomic weight of $\mathrm{Fe}=56 \mathrm{~g} / \mathrm{mol}$ ]

$5.8 \mathrm{~g} / \mathrm{cm}^3$

$1.5 \mathrm{~g} / \mathrm{cm}^3$

$2.9 \mathrm{~g} / \mathrm{cm}^3$

$8.5 \mathrm{~g} / \mathrm{cm}^3$

A compound can crystallise in two forms $\alpha$ and $\beta$ which are fcc and bcc, respectively. The $\alpha$-form has side length of 2 pm and the $\beta$-form has side length of 4 pm . The ratio of their density $\frac{\rho_\alpha}{\rho_\beta}$ is

At atmospheric pressure and very low temperature, water crystallises to

Intercepts of a plane in crystal is given by $a, b / 2,3 c$ in a simple cubic unit cell. The miller indices are

$(1 \,\, \,\,\,3 \,\, \,\,\,2)$

$(2 \,\, \,\,\,6 \,\,\,\,\,1)$

$\left(\begin{array}{lll}1 & 2 & 3\end{array}\right)$

$\left(\begin{array}{lll}3 & 6 & 1\end{array}\right)$

In a bcc lattice having the edge length of 200 pm , the cation has the radius of 70 pm . The radius ratio of $\frac{r^{+}}{r^{-}}$is (Given, $\sqrt{2}=1.4, \sqrt{3}=1.7$ and $\sqrt{6}=2.4$ )

Copper crystallises in ccp arrangement and accepted value of metal ion radius was found to be $1.14 \mathop {\rm{A}}\limits^{\rm{o}}$. Calculate the density of copper in grams per cubic centimetre. (Atomic weight of copper is 64 , $N_A=6 \times 10^{23}$ )