Chapter 2

The unit of surface tension is (a) Joule \(\mathrm{m}^{-1}\) (b) \(\mathrm{N} \mathrm{m}^{-1}\) (c) \(\mathrm{erg} \mathrm{cm}^{-1}\) (d) none of these

A drop of liquid acquires a spherical shape because of (a) its tendency to maximize its surface area (b) its tendency to acquire minimum surface area (c) its viscous nature (d) none of these

Liquefied metals contain (a) metal anions only (b) metal cations only (c) metal kernels and mobile electrons (d) metal atoms only

Capillary cation of liquids can be explained on the basis of its (a) surface tension (b) resistance to flow (c) heat of vaporization (d) all of these

SI units of coefficient of viscosity are (a) \(\mathrm{kg} \mathrm{s}^{-1} \mathrm{~m}^{-2}\) (b) \(\mathrm{g} \mathrm{m}^{-1} \mathrm{~s}^{-1}\) (c) \(\mathrm{kg} \mathrm{m}^{-1} \mathrm{~s}^{-1}\) (d) \(\mathrm{kg} \mathrm{cm}^{-1} \mathrm{~s}^{-1}\)

Poise is a unit of (a) viscosity (b) vapour pressure (c) surface tension (d) parachore value

Which of the following liquid has the highest vapour pressure or is most volatile? (a) HF (1) (b) \(\mathrm{NH}_{3}\) (1) (c) \(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}\) (1) (d) \(\mathrm{H}_{2} \mathrm{O}\)

The vapour pressure of the liquid depends upon (a) the amount of liquid taken (b) the temperature of the liquid (c) the volume of the vessel (d) both amount and temperature (e) all of these

When a liquid is evaporated (a) temperature of liquid decreases (b) temperature of the liquid increases (c) liquid molecules become more energetic (d) both (b) and (c)

When a liquid is heated (a) surface tension increases (b) surface tension is lowered (c) viscosity increases (d) surface tension is not effected

A substance \(A_{x} B_{y}\) crystallizes in a face-centred cubic (FCC) lattice in which atoms 'A' occupy each corner of the cube and atoms 'B' occupy the centres of each face of the cube. Identify the correct composition of the substance \(A_{x} B_{y^{\prime}}\) (a) \(\mathrm{AB}_{3}\) (b) \(\mathrm{A}_{4} \mathrm{~B}_{3}\) (c) \(\mathrm{A}_{3} \mathrm{~B}\) (d) composition cannot be specified

Which of the following statements is correct in context of point defects in a crystal? (a) \(\mathrm{AgCl}\) as well as \(\mathrm{CaF}_{2}\) has Schottky defects (b) AgCl as well as \(\mathrm{CaF}_{2}^{-}\)have anion Frenkel defects (c) \(\mathrm{AgCl}\) has cation Frenkel defects and \(\mathrm{CaF}_{2}\) has Schottky defects (d) \(\mathrm{AgCl}\) has cation Frenkel defects and \(\mathrm{CaF}_{2}\) has anion Frenkel defects

\(\mathrm{NaCl}\) shows Schottky defects and \(\mathrm{AgCl}\) Frenkel defects. Their electrical conductivity is due to (a) lower coorination number of \(\mathrm{NaCl}\) (b) higher coordination number of \(\mathrm{AgCl}\) (c) motion of ions and not the motion of electrons (d) motion of electrons and not the motion of ions

Pick out the incorrect statement: (a) \(\mathrm{NaCl}\) has \(8: 8\) coordination, while \(\mathrm{CsCl}\) is with \(6: 6\) coordination (b) In \(\mathrm{Na}_{2} \mathrm{O}\) each oxide ion is coordinated by \(8 \mathrm{Na}^{+}\) ions and each \(\mathrm{Na}\) ' ion by 4 oxide ions (c) \(\mathrm{NaCl}\) structure transform to \(\mathrm{CsCl}\) structure on heating (d) In \(\mathrm{CaF}_{2}\) structure, each \(\mathrm{F}^{-}\)ion is coordinated by \(4 \mathrm{Ca}^{2}\) ions and each \(\mathrm{Ca}^{4}\) ion is coordinated by \(8 \mathrm{~F}\) ions

If molar mass of \(\mathrm{AB}\) is \(95 \mathrm{~g} \mathrm{~mol}^{-1}\) and \(\mathrm{a}\) is edge length, then the density of crystal structure is (a) \(\frac{4 \times 95}{a^{3} \times N_{A}}\) (b) \(\frac{4 \mathrm{~N}_{\mathrm{A}}}{\mathrm{a}^{3} \times 95}\) (c) \(\frac{2 \times 95}{a^{3} \times N_{4}}\) (d) \(\frac{2 \mathrm{~N}_{\mathrm{A}}}{\mathrm{a}^{3} \times 95}\)

The radius ratio \(\left(\mathrm{r}^{+} / \mathrm{r}^{-}\right)\)of \(\mathrm{KF}\) is \(0.98\). The structure of \(\mathrm{KF}\) is similar to (a) \(\mathrm{NaCl}\) (b) \(\mathrm{CsCl}\) (c) \(\mathrm{ZnS}\) (d) both (a) and (b)

\(\mathrm{Na}_{2} \mathrm{O}\) has antifluorite structure. In \(\mathrm{Na}_{2} \mathrm{O}\), the coordination number of \(\mathrm{N}^{\mathrm{a}^{+}}\)and \(\mathrm{O}^{2-}\) are respectively (a) 4,4 (b) 6,6 (c) 4,8 (d) 8,8

In calcium fluoride structure, the coordination numbers of calcium and fluoride ions respectively are (a) 6 and 8 (b) 8 and 8 (c) 4 and 8 (d) 8 and 4

In a body-centred cubic arrangement, A ions occupy the centre while B ions occupy the corners of the cube. The formula of the solid is (a) \(\mathrm{AB}\) (b) \(\mathrm{AB}_{2}\) (c) \(\mathrm{A}_{2} \mathrm{~B}\) (d) \(\mathrm{AB}_{3}\)

If three elements A, B and C crystallized in cubic solid lattice with A atoms at corners, \(\mathrm{B}\) atoms at cube centres and \(\mathrm{C}\) atoms at the edges, the formula of the compound is (a) \(\mathrm{ABC}\) (b) \(\mathrm{ABC}_{3}\) (c) \(\mathrm{AB}_{3} \mathrm{C}\) (d) \(\mathrm{A}_{3} \mathrm{~B}_{2} \mathrm{C}_{3}\)

If the anions (b) form hexagonal close packing and cations (a) occupy only \(2 / 3\) octahedral holes in it, then the general formula of the compound is (a) \(\mathrm{AB}_{2}\) (b) \(\mathrm{A}_{2} \mathrm{~B}_{3}\) (c) \(\mathrm{A}_{3} \mathrm{~B}_{3}\) (d) \(\mathrm{A}_{2} \mathrm{~B}_{2}\)

In a spinel structure, oxides ions are cubical closest packed, whereas \(1 / 8\) of tetrahedral holes are occupied by cations \(\mathrm{A}^{2+}\) and \(1 / 2\) of octahedral holes are occupied by cations \(\mathrm{B}^{3}\) ions. The general formula of the compound having spinel structure is (a) \(\mathrm{AB}_{2} \mathrm{O}_{4}\) (b) \(\mathrm{A}_{2} \mathrm{~B}_{2} \mathrm{O}_{4}\) (c) \(\mathrm{A}_{2} \mathrm{~B}_{6} \mathrm{O}\) (d) \(\mathrm{A}_{4} \mathrm{~B}_{3} \mathrm{O}\)

In a cubic closed packed structure of mixed oxides, the lattice is made up of oxide ions, \(20 \%\) of tetrahedral Voids are occupied by divalent \(\mathrm{A}^{2+}\) ions and \(50 \%\) of the octahedral voids by trivalent \(\mathrm{B}^{3+}\). The formula of the oxide is? (a) \(\mathrm{A}_{4} \mathrm{~B}_{5} \mathrm{O}_{10}\) (b) \(\mathrm{A}_{2} \mathrm{~B}_{5} \mathrm{O}_{5}\) (c) \(\mathrm{A}_{2} \mathrm{BO}\) (d) \(\mathrm{A}_{4} \mathrm{~B}_{5} \mathrm{O}_{8}\)

A compound formed by elements A and B crystallizes in cubic structure where A atoms are at the corners or a cube and \(\mathrm{B}\) atoms are at the face centre. The formula of the compound is (a) \(\mathrm{AB}\) (b) \(\mathrm{AB}_{2}\) (c) \(\mathrm{AB}_{3}\) (d) \(\mathrm{AB}_{4}\)

The radius of \(\mathrm{Ag}^{+}\)ion is \(126 \mathrm{pm}\) while that of \(\mathrm{I}\) ion is \(216 \mathrm{pm}\). The coordination number of \(\mathrm{Ag}\) in \(\mathrm{AgI}\) is (a) 8 (b) 6 (c) 4 (d) 2

Which of the following crystals have \(6: 6\) coordination? (a) \(\mathrm{MnO}\) (b) \(\mathrm{NH}_{4} \mathrm{I}\) (c) \(\mathrm{ZnS}\) (d) none of these

\(\mathrm{TiO}_{2}\) (rutile) shows \(6: 3\) coordination. The solid having rutile like structure among the following is (a) \(\mathrm{KCl}\) (b) \(\mathrm{SnO}_{2}\) (c) \(\mathrm{ZnS}\) (d) none of these

\(\mathrm{M}_{2} \mathrm{X}\) have a structure closely related to that of fluorite. It is actually reverse of fluorite structure hence called antifluorite structure. In such a structure (a) \(\mathrm{F}\) ions occupy all the 8 octahedral voids (b) each \(\mathrm{F}^{-}\)is surrounded by \(4 \mathrm{Ca}^{2^{+}}\)in tetrahedral arrangement (c) larger cations occupy the position of \(\mathrm{F}\) - ions and smaller anions that of \(\mathrm{Ca}^{2+}\) ions. (d) smaller cations occupy the position of fluoride ions and larger anions that of \(\mathrm{Ca}^{2^{+}}\)ions

The number of atoms per unit cell in a BCC, a FCC and a simple cubic cell are respectively (a) \(1,4,2\) (b) \(2,4,1\) (c) \(4,1,2\) (d) \(4,2,2\)

The number of atoms per unit cell in a simple cubic, face-centred cubic and body-centred cubic are....... respectively (a) \(1,2,4\) (b) \(1,4,2\) (c) \(4,2,1\) (d) \(1,4,3\)

Amorphous substances show (i) short and long range order (ii) short range order (iii) long range order (iv) have no sharp melting point (a) (i) and (ii) are correct (b) (ii) and (iv) are correct (c) (ii), (iii) and (iv) are correct (d) (i) and (iv) are correct

A compound contains two types of atoms: \(\mathrm{X}\) and \(\mathrm{Y}\). It crystallizes in a cubic lattice with atoms \(\mathrm{X}\) at the corners of the unit cell and atoms \(\mathrm{Y}\) at the body centres. The simplest possible formula of this compound is: (a) XY (b) \(\mathrm{X}_{2} \mathrm{Y}_{2}\) (c) \(\mathrm{XY}_{6}\) (d) \(\mathrm{X}_{8} \mathrm{Y}\)

Which of the following statements is correct? (1) The coordination number of each type of ion in \(\mathrm{CsCl}\) crystal is 8 (2) A metal that crystallizes in BCC structure has a coordination number of 12 (3) A unit cell of an ionic crystal shares some of its ion with other units cells (4) the length of unit cell in \(\mathrm{NaCl}\) is \(552 \mathrm{pm}\) (r \(\mathrm{Na}^{+}=\) \(95 \mathrm{pm}, \mathrm{r} \mathrm{Cl}=181 \mathrm{pm}\) ) (a) 1,2 (b) 1,3 (c) 2,3 (d) 2,4

The second order Bragg diffraction of X-rays, with \(\lambda=1 \AA\) from a set of parallel planes in a metal, occurs at an angle of \(60^{\circ} .\) The distance between the scattering planes in the crystal is (a) \(2.00 \AA\) (b) \(1.00 \AA\) (c) \(0.575 \AA\) (d) \(1.15 \AA\)

The closet distance between two atoms (in terms of edge length) would be highest for which of unit cell, assuming the edge length of each unit cell of be 'a' (a) FCC unit cell (b) BCC unit cell (c) diamond unit cell (d) primitive cubic cell

A solid XY has NaCl structure. If radius of \(\mathrm{X}^{+}\)is 100 \(\mathrm{pm}\), the radius of \(\mathrm{Y}\)-ion is (a) \(136.6\) to \(241.6 \mathrm{pm}\) (b) \(341.6\) to \(134.6 \mathrm{pm}\) (c) \(128 \mathrm{pm}\) (d) \(136.8 \mathrm{pm}\)

The ionic radii of \(\mathrm{Rb}^{+}\)and \(\mathrm{I}^{-}\)are \(1.46 \AA\) and \(2.16 \AA\) respectively. The most probable type of structure exhibited by it is (a) \(\mathrm{CaF}_{2}\) type (b) \(\mathrm{ZnS}\) type (c) \(\mathrm{CsCl}\) type (d) \(\mathrm{NaCl}\) type

A solid has 3 types of atoms namely \(\mathrm{X}, \mathrm{Y}\) and \(\mathrm{Z}\). \(\mathrm{X}\) forms an FCC lattice with \(\mathrm{Y}\) atoms occupying all the tetrahedral voids and \(Z\) atoms occupying half the octahedral voids. The formula of the solid is (a) XYZ (b) \(\mathrm{X}_{2} \mathrm{Y}_{4} \mathrm{Z}\) (c) \(\mathrm{X}_{4} \mathrm{YZ}_{2}\) (d) \(X_{4} Y_{2} Z\)

Calculate the \(\lambda\) of X-rays which give a diffraction angle \(2 \theta=16.80^{\circ}\) for a crystal. (Given interplanar distance = \(0.200 \mathrm{~nm} ;\) diffraction \(=\) first order; \(\sin 8.40^{\circ}=0.1461\) ) (a) \(58.4 \mathrm{pm}\) (b) \(5.84 \mathrm{pm}\) (c) \(584 \mathrm{pm}\) (d) \(648 \mathrm{pm}\)

Match List I with List II and select the correct answer: \(\begin{array}{ll}\text { List I } & \text { List II }\end{array}\) \(\begin{aligned}&\text { (Shape) } & \text { (Radius ratio) }\end{aligned}\) 1\. Planar triangle (i) \(0.732\) 2\. Square planar (ii) \(0.225\) 3\. Body-centred cubic (iii) \(0.155\) 4\. Tetrahedral (iv) \(0.414\) \(\begin{array}{llll}1 & 2 & 3 & 4\end{array}\) (a) (iii) (ii) (i) (iv) (b) (iii) (iv) (i) (ii) (c) (ii) (i) (iv) (iii) (d) (ii) (iv) (iii) (i)

In a compound XY, the ionic radii \(\mathrm{X}^{+}\)and \(\mathrm{Y}\) are \(88 \mathrm{pm}\) and \(200 \mathrm{pm}\) respectively. What is the coordination number of \(\mathrm{X}^{+}\)? (a) 4 (b) 6 (c) 8 (d) 10

The edge length of unit cell of a metal having molecular weight \(75 \mathrm{~g} / \mathrm{mol}\) is \(5 \AA\) A which crystallizes in cubic lattice. If the density is \(2 \mathrm{~g} / \mathrm{cc}\) then find the radius of metal atom. \(\left(\mathrm{NA}=6 \times 10^{23}\right)\). Give the answer in \(\mathrm{pm}\). (a) \(116.5 \mathrm{pm}\) (b) \(316.5 \mathrm{pm}\) (c) \(216.5 \mathrm{pm}\) (d) \(416.5 \mathrm{pm}\)

Sodium metal crystallizes as a body-centred cubic lattice with the cell edge \(4.29 \AA\). What is the radius of sodium atom? (a) \(2.371 \times 10^{-7} \mathrm{~cm}\) (b) \(1.857 \times 10^{8} \mathrm{~cm}\) (c) \(3.817 \times 10^{-8} \mathrm{~cm}\) (d) \(7.312 \times 10^{-7} \mathrm{~cm}\)

A metallic element crystallizes into a lattice containing a sequence of layers of ABABAB... Any packing of spheres leaves out voids in the lattice. What percentage by volume of this lattice is empty space? (a) \(26 \%\) (b) \(74 \%\) (c) \(50 \%\) (d) \(85 \%\)

Gold (Au) crystallizes in cubic close packed (FCC). The atomic radius of gold is \(144 \mathrm{pm}\) and the atomic mass of \(\mathrm{Au}=197.0 \mathrm{amu}\). The density of \(\mathrm{Au}\) is (a) \(19.4 \mathrm{~g} \mathrm{~cm}^{-3}\) (b) \(194 \mathrm{~g} \mathrm{~cm}^{-3}\) (c) \(39.4 \mathrm{~g} \mathrm{~cm}^{-3}\) (d) \(0.194 \mathrm{~g} \mathrm{~cm}^{-3}\)

An alloy of copper, silver and gold is found to have copper constituting the ccp lattice. If silver atoms occupy the edge centres and gold is present at body centre, the alloy will have the formula (a) \(\mathrm{Cu}_{4} \mathrm{Ag}_{4} \mathrm{Au}\) (b) \(\mathrm{Cu} \mathrm{Ag} \mathrm{Au}\) (c) \(\mathrm{Cu}_{4} \mathrm{Ag}_{2} \mathrm{Au}\) (d) \(\mathrm{Cu}_{4} \mathrm{Ag}_{3} \mathrm{Au}\)

At room temperature, sodium crystallizes in a \(\mathrm{BCC}\) lattice with the cell edge (a) \(4.24 \AA\). Find the density of sodium. (Atomic wt of \(\mathrm{Na}=23\) ) (a) \(2.01 \mathrm{~g} / \mathrm{cm}^{3}\) (b) \(1.002 \mathrm{~g} / \mathrm{cm}^{3}\) (c) \(3.003 \mathrm{~g} / \mathrm{cm}^{3}\) (d) \(2.004 \mathrm{~g} / \mathrm{cm}^{3}\)

The density of solid argon is \(1.65 \mathrm{~g} / \mathrm{mL}\) at \(-233^{\circ} \mathrm{C}\). If the argon atom is assumed to be sphere of radius \(1.54 \times\) \(10^{-8} \mathrm{~cm}\), what percentage of solid argon is apprarently empty space? (Atomic wt of \(\mathrm{Ar}=40\) ) (a) \(32 \%\) (b) \(52 \%\) (c) \(62 \%\) (d) \(72 \%\)

Identify the correct statements. (a) The size of octahedral site is given by \(r=0.414 R\) where \(\mathrm{r}\) is the radius of octahedral hole and \(\mathrm{R}\) is the radius of spheres enclosing it. (b) In CCP or HCP arrangement, there are two octahedral sites per closely packed sphere. (c) The centres of octahedral sites lie at the mid point of the sides and at the body centre of face centred cubic unit cell. (d) The radius of tetrahedral hole (r) and that of spheres (R) forming it are related as \(\mathrm{r}=0.155 \mathrm{R}\).

The correct statements regarding defects in solids are, (a) Schottky defects affect the density of solid. (b) Trapping of an electron in the lattice leads to the formation of \(\mathrm{F}\) - center. (c) Frenkel defect is a dislocation effect. (d) Frenkel defect is usually favoured by a very small difference in the sizes of cation and anion.