Chapter 2

Which type of crystals contains the maximum number of Bravais lattices ? (a) Cubic (b) Triclinic (c) Orthorhombic (c) Tetragonal

A gas behaves like an ideal gas at (a) high pressure and low temperature (b) high pressure and high temperature (c) low pressure and high temperature (d) low pressure and low temperature

A compound is formed by elements \(A\) and \(B\) and is cubic. \(A\) atoms are at the comers and \(B\) atoms are at the face centre. The formula of the compound is (a) \(A B\) (b) \(A B_{2}\) (c) \(A B_{3}\) (d) \(A_{3} B\)

To which of the following gaseous mixtures is Dalton's law not applicable ? (a) \(\mathrm{Ne}+\mathrm{He}+\mathrm{SO}_{2}\) (b) \(\mathrm{NH}_{3}+\mathrm{HCl}+\mathrm{HBr}\) (c) \(\mathrm{O}_{2}+\mathrm{N}_{2}+\mathrm{CO}_{2}\) (d) \(\mathrm{N}_{2}+\mathrm{H}_{2}+\mathrm{O}_{2}\)

In a compound, oxide ions have ecp arrangement. The cations \(\mathrm{A}\) are present in one-eighth of the tetrahedral holes and cations B occupy half the octahedral holes. The simplest formula of the compound is (a) \(\mathrm{AB}_{2} \mathrm{O}_{4}\) (b) \(\mathrm{A}_{2} \mathrm{BO}_{4}\) (c) \(\mathrm{ABO}_{2}\) (d) \(\mathrm{ABO}_{4}\)

The density of a gas at \(27^{\circ} \mathrm{C}\) and \(1 \mathrm{~atm}\) is \(d\). Pressure remaining constant, at which of the following temperatures will its density become \(0.75 d ?\) (a) \(20^{\circ} \mathrm{C}\) (b) \(30^{\circ} \mathrm{C}\) (c) \(400 \mathrm{~K}\) (d) \(300 \mathrm{~K}\)

The Schottky defect in a crystal is observed when (a) an ion leaves its normal site and occupies an interstitial site b) equal number of cations and anions are missing from the lattice (c) unequal number of cations and anions are missing from the lattice (d) density of the crystal is increased

The values of \(a\) for the gases oxygen, carbondioxide, nitrogen and methane are respectively, \(1.360,3.640,1.390\) and \(2.253 \mathrm{~L}^{2}\) atm \(\mathrm{mol}^{-1}\). Which gas can be the most easily liquefied? (a) oxygen (b) nitrogen (c) carbondioxide (d) methane

A \(10 \mathrm{~L}\) cylinder of nitrogen at \(4.0\) atm pressure and \(27^{\circ} \mathrm{C}\) developed a leak. When the leak was repaired \(2.36\) atm of nitrogen remained in the cylinder still at \(27^{\circ} \mathrm{C}\). How many grams of nitrogen escaped ? (a) \(18.7 \mathrm{~g}\) (b) \(0.67 \mathrm{~g}\) (c) \(52.6 \mathrm{~g}\) (d) \(10.0 \mathrm{~g}\)

Potassium metal crystallizes in the form of a body-centred cubic structure. The number of nearest-neighbor atoms for each potassium atom in the solid is (a) Four (b) Six Twelve (c) Twelve \(\quad\) (d) Eight

The temperature at which real gases obey the ideal gas laws over a wide range of pressures is called (a) Critical temperature (b) Inversion, temperature (c) Boyle temperature (d) Reduced temperature

In a compound, oxide has hep arrangementand the cations \(\mathrm{M}\) occupy two-third octahedral voids. The formula of the compound is (a) \(\mathrm{M}_{3} \mathrm{O}\) (b) \(\mathrm{M}_{3} \mathrm{O}_{2}\) (c) \(\mathrm{M}_{2} \mathrm{O}_{3}\) (d) \(\mathrm{M}_{3} \mathrm{O}_{4}\)

At a given temperature, \(\rho_{x}=3 \rho_{y}\) and \(M_{y}=2 M_{x}\), where \(\rho\) and \(M\) stand for density and molecular mass, respectively. The ratio of their pressures \(P_{I} / P_{y}\) would be (a) \(1 / 4\) (b) \(4 / 1\) (c) \(6 / 1\) (d) \(1 / 6\)

In a compound \(\mathrm{XY}_{2} \mathrm{O}_{4}\), oxide ions are arranged in cop and cations \(\mathrm{X}\) are present in octahedral voids. Cations \(\mathrm{Y}\) are equally distributed between octahedral and tetrahedral voids. The fraction of the octahedral voids occupied is (a) \(1 / 2\) (b) \(1 / 4\) (c) \(1 / 8\) (d) \(1 / 6\)

Which of the following gases will have the highest rate of diffusion ? (a) \(\mathrm{O}_{2}\) (b) \(\mathrm{CO}_{2}\) (c) \(\mathrm{NH}_{3}\) (d) \(\mathrm{N}_{2}\)

The second onler Bragg diffraction of \(X\)-rays with \(\lambda=1.00 \mathrm{~A}\) from a set of parallel planes in a meial accurs at an angle of \(60^{\circ}\). The distance between the scattering planes in the crystal is (a) \(0.575 \mathrm{~A}\) (b) \(1.00 \mathrm{~A}\) (c) \(2.00 \mathrm{~A}\) (d) \(1.15 \AA\)

How many nearest neighbours are there in a body-centered cubic packing ? (a) Two (b) four (Q) eight (d) twelve

A I \(\mathrm{dm}^{3}\) sample of air at a pressure of \(1 \mathrm{~atm}\) and \(27^{\circ} \mathrm{C}\) weighs \(0.012 \mathrm{~kg}\). Calculate the effective molecular weight of air (in \(g / \mathrm{mol}\) ) if air behaves as an ideal gas. (a) \(29.6\) (b) \(30.6\) (c) \(28.6\) (d) \(31.6\)

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

Calculate the ionic radius of a \(\mathrm{Cs}^{+}\)ion, assuming that the cell- edge length for \(\mathrm{CsCl}\) is \(0.4123 \mathrm{~nm}\) and that the ionic radius of a \(\mathrm{Cl}\) ion is \(0.181 \mathrm{~nm}\). (a) \(0.176 \mathrm{~nm}\) (b) \(0.231 \mathrm{~nm}\) (c) \(0.352 \mathrm{~nm}\) (d) \(0.116 \mathrm{~nm}\)

If pressure of a gas contained in a closed vessel is increased by \(0.4 \%\) when heated by \(1^{\circ} \mathrm{C}\). its initial temperature must be (a) \(250 \mathrm{~K}\) (b) \(250^{\circ} \mathrm{C}\) (c) \(2500 \mathrm{~K}\) (d) \(25^{\circ} \mathrm{C}\)

At what temperature will the molar \(\mathrm{KE}\) of \(0.3\) mol of He be the same as that of \(0.4 \mathrm{~mol}\) of argon at \(400 \mathrm{~K} ?\) (a) \(700 \mathrm{~K}\) (b) \(500 \mathrm{~K}\) (c) \(533.33 \mathrm{~K}\) (d) \(400 \mathrm{~K}\)

Zinc blende structure is obtained when \(\mathrm{Zn}^{2+}\) occupies (a) All tetrahedral sites (b) Half tetrahedral sites (c) All octahedral sites (d) Half octahedral sites

Equal masses of methane and hydrogen are mixed in an empty container at \(25^{\circ} \mathrm{C}\). The fraction of the total pressure exerted by hydrogen is: (a) \(1 / 2\) (b) \(8 / 9\) (c) \(1 / 9\) (d) \(16 / 17\)

The tetrahedral void has a coordination number of (a) two (b) three four (c) four (d) eight

If \(1000 \mathrm{~mL}\) of gas \(\mathrm{A}\) at 600 torr and \(500 \mathrm{~mL}\) of gas \(\mathrm{B}\) at 800 torr are placed in a 2 litre flask, the final pressure will be: (a) 2000 torr (b) 1000 torr (c) 500 torr (d) 400 torr

A gas deviates maximum from the ideal gas laws at (a) High temperature and high pressure (b) Low temperature and low pressure (c) High temperature and low pressure (d) Low temperature and high pressure

In a solid, AB having \(\mathrm{NaCl}\) structure. A atoms occupy the corners of the cubic unit cell. If all the face-centred atoms along one of the axes are removed, then the resultant stoichiometry of the solid is (a) \(\mathrm{AB}_{3}\) (b) \(\mathrm{A}_{2} \mathrm{~B}\) (c) \(\mathrm{A}_{4} \mathrm{~B}_{1}\) (d) \(\mathrm{A}_{1} \mathrm{II}_{4}\)

At constant temperature, if pressure increases by \(1 \%\), the percentage decrease in, volume is (a) \(1 \%\) (b) \((100 / 101) \%\) (c) \((1 / 101) \%\) (d) \((1 / 100) \%\)

Two glass bulbs ' \(X^{\prime}\) and \(^{\prime} Y^{\prime}\) are connected by a very small tube having a stop cock. Bulb \(X\) has a volume of \(100 \mathrm{~cm}^{3}\) and contains the gas, while bulb \(Y\) is empty. On opening the stop cock, the pressure falls down by \(60 \%\). The volume of bulb \(Y\) must be (a) \(150 \mathrm{~cm}^{3}\) (b) \(250 \mathrm{~cm}^{3}\) (c) \(100 \mathrm{~cm}^{3}\) (d) \(125 \mathrm{~cm}^{3}\)

How many formula units of \(\mathrm{CsCl}\) are present in the unit cell ? (a) 1 (b) 2 (c) 4 (d) 6

The rms speed of \(\mathrm{N}_{2}\) molecules in a gas is \(u\). If the temperature is doubled and the nitrogen molecules dissociate into nitrogen atoms, the rms speed becomes (a) \(u / 2\) (b) \(2 u\) (c) \(4 u\) (d) \(14 u\)

An fec cubic cell contains eight \(\mathrm{X}\) atoms at the cell and six \(\mathrm{Y}\) atoms at the faces. What is the cmpirical formula of the solid? (a) \(\mathrm{X}_{3} \mathrm{Y}_{4}\) (b) \(X_{3} Y\) (c) \(\mathrm{XY}_{3}\) (d) \(\mathrm{X}_{4} \mathrm{Y}_{3}\)

Oxygen (one \(\mathrm{dm}^{3}\) at 1 atm) takes 2 min to effuse through an orifice. How much time (in minutes) will be taken by \(\mathrm{N}_{2}, \mathrm{He}\) and \(\mathrm{SF}_{6}\) vapours to effuse under the same conditions? (a) \(0.7,1.87,4.27\) (b) \(4.27,0.7,1.87\) (c) \(1.87,0.7,4.27\) (d) \(4.27,1.87,0.7\)

A solid has a structure in which \(\mathrm{W}\) atoms are located at the corners of the cubic lattice, \(\mathrm{O}\) atoms at the center of the edges and \(\mathrm{Na}\) atom at the center of the cube. The formula of the compound is (a) \(\mathrm{NaWO}_{2}\) (b) \(\mathrm{Na}_{2} \mathrm{WO}_{3}\) \(\mathrm{NaWO}_{3}\) (d) \(\mathrm{NaWO}_{4}\)

Which of the following is arranged in order of increasing molecular speed? (a) \(\mathrm{HBr}<\mathrm{O}_{2}<\mathrm{N}_{2}<\mathrm{H}_{2}\) (b) \(\mathrm{H}_{2}<\mathrm{N}_{2}<\mathrm{O}_{2}<\mathrm{HBr}\) (c) \(\mathrm{O}_{2}<\mathrm{HBr}<\mathrm{N}_{2}<\mathrm{H}_{2}\) (d) \(\mathrm{N}_{2}<\mathrm{O}_{2}<\mathrm{HBr}<\mathrm{H}_{2}\)

A solid is made of two elements \(\mathrm{A}\) and \(\mathrm{B}\). The atoms of \(\mathrm{A}\) are arranged in a cep structure and those of B occupy all the tetrahedral sites. The formula of the compound is (a) \(\mathrm{AB}_{2}\) (b) \(\mathrm{A}_{2} \mathrm{~B}\) (c) \(\mathrm{A}_{2} \mathrm{~B}_{3}\) (d) \(\mathrm{A}_{3} \mathrm{~B}_{2}\)

A compound alloy of gold and copper crystallizes in a cubic lattice in which the gold atoms occupy the lattice points at the corners of a cube and a copper atom occupies the center of each cube face. The formula of this compound is (a) \(\mathrm{Au}_{3} \mathrm{Cu}\) (b) \(\mathrm{AuCu}_{3}\) (c) \(\mathrm{Au}_{4} \mathrm{Cu}\) (d) \(\mathrm{AuCu}_{2}\)

In which of the following pairs of the molecules (gaseous) have the same root mean square speed ? (a) He and \(\mathrm{Ar}\) (b) \(\mathrm{NO}_{2}\) and \(\mathrm{N}_{2} \mathrm{O}_{4}\) (c) \(\mathrm{O}_{2}\) and \(\mathrm{O}_{3}\) (d) \(\mathrm{N}_{2}\) and \(\mathrm{CO}\)

Which of the following solids is amorphous ? (a) Fe metal (b) Fused quartz (e)' Wurtzite (d) NiAs

Equal masses of \(\mathrm{CH}_{4}\) and \(\mathrm{O}_{2}\) are mixed in an empty container at \(25^{\circ}\). The fraction of the total pressure exerted by oxygen is: (a) \(1 / 3\) (b) \(1 / 2\) (c) \(2 / 3\) (d) \((1 / 3) \times(273 / 298)\)

An ionic compound has a unit cell consisting of ' \(A\) ' ions at the corners of a cube and 'B' ions at the centres of the face of the cube. The empirical formula for this compound would be (a) \(\mathrm{AB}\) (b) \(\mathrm{A}_{2} \mathrm{~B}\) (c) \(\mathrm{AB}_{3}\) (d) \(\mathrm{A}_{3} \mathrm{~B}\)

When a compressed gas is allowed to expand through a porous plug at a temperature above its inversion temperature, there is (a) a fall in temperature (b) a rise in temperature (c) neither a fall nor a rise in temperature (d) a fall in temperature first, followed by a rise

An element (atomic mass \(=100 \mathrm{~g} / \mathrm{mol}\) ) having bce structure has unit cell edge \(400 \mathrm{pm}\). The density of the element is (a) \(10.376 \mathrm{~g} / \mathrm{cm}^{3}\) (b) \(5.1888 \mathrm{~g} / \mathrm{cm}^{3}\) (c) \(7.289 \mathrm{~g} / \mathrm{cm}^{3}\) (d) \(2.144 \mathrm{~g} / \mathrm{cm}^{3}\)

As temperature is raised from \(20^{\circ}\) to \(40^{\circ}\), the average kinetic energy of neon atoms changes by a factor of which of the following? (a) \(\frac{1}{2}\) (b) 2 (c) \(\frac{313}{293}\) (d) \(\sqrt{\frac{313}{293}} \mid\)

If \(\mathrm{NaCl}\) is doped with \(10^{-4}\) mol \(\%\) of \(\mathrm{SrCl}_{2}\), the concentration of cation vacancies will be \(\left(N_{A}=6.023 \times 10^{23}\right)\) (a) \(6.02 \times 10^{16} \mathrm{~mol}^{-1}\) (b) \(6.02 \times 10^{17} \mathrm{~mol}^{-1}\) (c) \(6.02 \times 10^{14} \mathrm{~mol}\) (d) \(6.02 \times 10^{15} \mathrm{~mol}^{-1}\)

The density of neon will be maximum at (a) NTP (b) \(0^{\circ} \mathrm{C}, 2 \mathrm{~atm}\) (c) \(273^{\circ} \mathrm{C}, 1 \mathrm{~atm}\) (d) \(273^{\circ} \mathrm{C}, 2 \mathrm{~atm}\)

Total volume of atoms present in a face-centerd cubic unit cell of a metal is ( \(r\) is atomic radius) (a) \((20 / 3) \pi \mathrm{r}^{3}\) (b) \((24 / 3) \pi r^{3}\) (c) \((12 / 3) \pi \mathrm{r}^{3}\) (d) \((16 / 3) \pi r^{3}\)

A bottle of ammonia and a bottle of dry hydrogen chloride connected through a long tube are opened simultaneously at both ends, the white ammonium chloride ring first formed will be (a) at the center of the tube (b) near the hydrogen chloride bottle (c) near the ammonia bottle (d) throughout the length of the tube

The surface tension of which of the following liquids is maximum ? (a) \(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}\) (b) \(\mathrm{CH}_{3} \mathrm{OH}\) (c) \(\mathrm{H}_{2} \mathrm{O}\) (d) \(\mathrm{C}_{6} \mathrm{H}_{6}\)