Chapter 2

Which of the following is not a feature of solids? (a) definite mass and volume (b) frequent fluidity (c) rigidity (d) definite shape

Which of the following is not a characteristic of amorphous solids? (a) have sharp melting point (b) have non-orderly or very short-range orderly arrangement (c) show isotropy (d) have tendency to undergo irregular cleavage

Which of the following is not a property of crystalline solids? (a) show isotropy (b) have a sharp melting point (c) have anisotropic nature (d) have a long-range orderly arrangement

Which of the following is a non-crystalline solids' pair? (a) diamond, wood (b) glass, table salt (c) wood, glass (d) sucrose, glass

Which of the following is a molecular solid? (a) \(\mathrm{I}_{2}\) (b) wax (c) ice (d) all of these

Which type of solids here are generally good conductors of electricity? (a) metallic (b) covalent (c) ionic (d) molecular

Among the following which is/are not crystalline solid(s)? (a) glass (b) sodium chloride (c) sucrose (d) both (b) and (c)

Which of the following has hexagonal structure? (a) diamond (b) sodium chloride (c) graphite (d) both (a) and (c)

The total number of crystal systems and the number of Bravais lattices are respectively (a) 7,7 (b) 7,14 (c) 14,14 (d) 9,16

Out of seven crystal systems how many can have body-centred unit cell? (a) 4 (b) 2 (c) 3 (d) 5

Among the following unit cells given below, which one has the highest symmetry? (a) cubic (b) monoclinic (c) hexagonal (d) orthorhombic

The total elements of symmetry in a cube are (a) 23 (b) 14 (c) 25 (d) 16

In which of the following crystal systems the endcentred unit cell exists? (a) monoclinic (b) triclinic (c) cubic (d) all of these

The empty space left in a hexagonal close packing of spheres in three dimensions is (a) \(64 \%\) (b) \(26 \%\) (c) \(14 \%\) (d) \(52.4 \%\)

Which one of the following is not a close packed arrangement? (a) \(\mathrm{BCC}\) (b) \(\mathrm{ccp}\) (c) \(\mathrm{hcp}\) (d) all of these

The void formed by closed packed array of spheres located at the alternate corners of each face is (a) octahedral void (b) tetrahedral void (c) triangular void (d) both (a) and (b)

The pattern of successive layers of cep arrangement can be designated as (a) \(\mathrm{AB}, \mathrm{ABC}, \mathrm{AB}, \mathrm{ABC} \ldots\) (b) \(\mathrm{AB}, \mathrm{AB}, \mathrm{AB} \ldots\) (c) \(\mathrm{AB}, \mathrm{BA}, \mathrm{AB}, \mathrm{BA} \ldots\) (d) \(\mathrm{BC}, \mathrm{ABC}, \mathrm{ABC} \ldots\)

In simple cubic crystal the radius ratio should be (a) \(\geq 0.732\) (b) \(\leq 0.732\) (c) \(\leq 0.424\) (d) \(\leq 0.225\)

If \(\mathrm{R}\) is the radius of the sphere in the close packed arrangement and \(\mathrm{r}\) is the radius of the tetrahedral void, then (a) \(\mathrm{R}=0.414 \mathrm{r}\) (b) \(\mathrm{r}=0.224 \mathrm{R}\) (c) \(\mathrm{R}=0.225 \mathrm{r}\) (d) \(\mathrm{r}=0.414 \mathrm{R}\)

Which of the following statements about the \(\mathrm{NaCl}\) crystal is correct? (a) \(\mathrm{Cl}\) ions are present at the corners and \(\mathrm{Na}^{+}\)ions at the body-centre (b) \(\mathrm{Cl}\) ions adopt bec arrangement (c) \(\mathrm{Cl}\) ions are packed following ABC ABC pattern of hexagonal close packing (d) \(\mathrm{Na}^{+}\)ions are at the edge centres only

The coordination number of \(\mathrm{Zn}^{2+}\) and \(\mathrm{S}^{2}\) ions in the zinc blende (ZnS) type structure is (a) \(6: 8\) (b) \(4: 4\) (c) \(4: 8\) (d) \(8: 8\)

Which among the following is likely to have Schottky defect? (a) \(\mathrm{ZnS}\) (b) \(\mathrm{AgBr}\) (c) \(\mathrm{NaCl}\) (d) none of these

\(\mathrm{ZnO}\) is white when cold and yellow when heated. It is due to the development of (a) metal excess defect (b) Frenkel defect (c) Schottky defect (d) both (b) and (c)

Which of the following is not correct consequences of Schottky defect? (a) stability of crystal decreases (b) density decreases (c) electrical conductivity increases (d) lattice energy of crystal increases

In Schottky defect (a) a lattice site is occupied by electron (b) the radius ratio, \(\mathrm{r}^{+} / \mathrm{r}^{-}\), is low (c) some of lattice sites are vacant (d) an ion occupies interstitial position between lattice points

In a closed packed array of \(\mathrm{N}\) spheres, the number of tetrahedral holes are (a) \(\mathrm{N}\) (b) \(2 \mathrm{~N}\) (c) \(\frac{\mathrm{N}}{2}\) (d \(\frac{\mathrm{N}}{4}\)

Which defect causes decrease in the density of a crystal? (a) Schottky (b) F-centre (c) Frenkel (d) Interstitial

Frenkel defect is noticed in (a) \(\mathrm{ZnS}\) (b) AgI (c) \(\mathrm{AgBr}\) (d) all of these

The defect when an ion occupies an interstitial position in the crystal lattice is called (a) Schottky defect (b) Crystal defect (c) Frenkel defect (d) none of these

In \(\mathrm{CaF}_{2}\) structure, \(\mathrm{Ca}^{2}\) ions form ccp arrangement and F- ions occupy (a) half the tetrahedral voids (b) all tetrahedral voids (c) half the octahedral voids (d) all octahedral voids

The general formula of an ionic compound crystallizing in zinc blende structure is (a) \(\mathrm{AB}_{3}\) (b) \(\mathrm{AB}_{2}\) (c) \(\mathrm{A}_{2} \mathrm{~B}_{2}\) (d) \(\mathrm{AB}\)

Which of the following statements is not correct? (a) The density of the crystal exhibiting Frenkel defect is less as compared to that of the perfect crystal (b) The Schottky defects are more common in ionic compounds with high coordination numbers and where the sizes of ions are small (c) In alkali halides, Frenkel defects are not found (d) The density of the crystal exhibiting Schottky defect is less as compared to that of the perfect crystal

Which of the following statements is not correct? (a) Heating of zinc oxide leads to the formation of a yellow coloured non- stoichiometric compound (b) The creation of cationic holes in ionic crystals imparts electrical conductivity to such crystals (c) The compound ferrous oxide can be prepared in its stoichiometric composition (d) Silver bromide shows both types of Schottky and Frenkel defects

On heating some polar crystals, weak electric current is produced. It is termed as (a) superconductivity (b) piezoelectricity (c) photoelectric current (d) none of these

Mark the correct statement (a) CsCl crystal show Schottky defect (b) Crystals having F-centres are coloured and paramagnetic (c) Photo sensitivity of AgBr is due to the presence of Frenkel defect in its crystals (d) all of these are correct

Which substance will conduct electric current in the solid state? (a) Diamond (b) Graphite (c) Sodium chloride (d) Iodine

The substance which possesses zero resistance at \(0 \mathrm{~K}\) is called (a) Super conductor (b) Insulator (c) Conductor (d) Semiconductor

In which of the following structures, the cation has maximum coordination number? (a) \(\mathrm{NaCl}\) (b) \(\mathrm{Na}_{2} \mathrm{O}\) (c) zinc blende (d) \(\mathrm{CaF}_{2}\)

In the zinc blende structure \((\mathrm{ZnS}), \mathrm{S}^{2}\) adopt ccp arrangement and \(\mathrm{Zn}^{2+}\) occupy (a) Alternate tetrahedral sites (b) Octahedral sites (c) Tetrahedral sites (d) Both octahedral and tetrahedral sites

An example of ferroelectric substance is (a) Tourmaline (b) Quartz (c) Barium titanate (d) Lead zirconate

An example of a ferromagnetic oxide is (a) \(\mathrm{TiO}_{2}\) (b) \(\mathrm{CrO}_{2}\) (c) \(\mathrm{Mn}_{2}^{2} \mathrm{O}_{7}\) (d) \(\mathrm{Fe}_{3} \mathrm{O}_{4}^{2}\)

If the alignment of magnetic moments in a substance is in a compensatory way so as to give zero net magnetic moment, then the substance is said to be (a) Anti-ferromagntic (b) Diamagnetic (c) Ferrimagnetic (d) Ferromagnetic

Which of the following is a ferrite? (a) \(\mathrm{MgFe}_{2} \mathrm{O}_{4}\) (b) \(\mathrm{Zn}_{3} \mathrm{FeO}_{4}\) (c) \(\mathrm{AlFe}_{2} \mathrm{O}_{4}\) (d) \(\mathrm{Na}_{2} \mathrm{Fe}_{2} \mathrm{O}_{4}\)

An example of anti-ferroelectric substance is (a) \(\mathrm{Fe}_{3} \mathrm{O}_{4}\) (b) \(\mathrm{PbZrO}_{3}\) (c) \(\mathrm{KH}_{2} \mathrm{PO}_{4}\) (d) \(\mathrm{BaTiO}_{3}\)

AB ABA... represents an arrangement of layers called (a) cubic closed packing (b) fluorite closed packing (c) hexagonal closed packing (d) body-centred cubic packing

\(\mathrm{CaO}\) and \(\mathrm{NaCl}\) have same crystal structure and nearly the same ionic radii. If \(X\) is the lattice energy of \(\mathrm{NaCl}\), the lattice energy of \(\mathrm{CaO}\) is very nealy (a) \(\mathrm{X}\) (b) \(2 \mathrm{X}\) (c) \(4 \mathrm{X}\) (d) \(\mathrm{X} / 4\)

Which of the following propertes of liquids is concerned with internal resistance to its flow? (a) viscosity (b) parachore value (c) refractive index (d) surface tension

The unit of surface tension is (a) Joule \(\mathrm{m}^{-1}\) (b) \(\mathrm{N} \mathrm{m}^{-1}\) (c) \(\operatorname{erg} \mathrm{cm}^{-1}\) (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