Deck 13: The Chemistry of Solids

Question 1

What is the distance,in atomic radii,along any edge of a body-centered cubic unit cell?

A)
B) 2 $\times$ r
C) 4 $\times$ r
D)
E) r

Answer 1

Question 2

Gold (atomic mass 197.0 g/mol),with an atomic radius of 144.2 pm,crystallizes in a face-centered cubic lattice.What is the density of gold?

A) 9.65 g/cm³
B) 1.21 g/cm³
C) 4.82 g/cm³
D) 2.41 g/cm³
E) 19.3 g/cm³

Answer 2

19.3 g/cm³

Question 3

Which of the following statements is/are CORRECT?
1)Of the four unit cell structures in which metals crystallize,three are based on the cubic unit cell and the fourth is the hexagonal unit cell.
2)Transition metals with high densities,especially those in period 6,preferentially crystallize with a primitive cubic cell structure.
3)The preferred crystal structure of the Group 1A metals is face-centered cubic.

A) 1 only
B) 2 only
C) 3 only
D) 1 and 2
E) 1,2,and 3

Answer 3

1 only

Question 4

Which one of the following statements is INCORRECT?

A) Polonium is the only metal that has a primitive cubic lattice.
B) The lattice structure of the alkali metals is body-centered cubic.
C) Many metals can crystallize in more than one type of crystal lattice.
D) Metals with a body-centered cubic lattice contain a net of four metal atoms per unit cell.
E) A hexagonal close packed structure is not an example of a cubic unit cell.

Question 5

Potassium crystallizes in the body-centered cubic system.If the edge of the unit cell is 524 pm,what is the radius of a potassium atom in picometers?

A) 227 pm
B) 908 pm
C) 1210 pm
D) 1050 pm
E) 98.3 pm

Question 6

Nickel has a face-centered cubic cell,and its density is 8.90 g/cm³.What is the radius (in pm)of a nickel atom? (The molar mass of nickel is 58.69 g/mol)

A) 62.3 pm
B) 88.1 pm
C) 125 pm
D) 249 pm
E) 535 pm

Question 7

For a metal that crystallizes in a body-centered cubic unit cell,what percentage of the space in the cell is occupied by the metal atoms?

A) 47%
B) 52%
C) 68%
D) 74%
E) 87%

Question 8

Rhodium crystallizes with a face-centered cubic unit cell.If the edge length of the unit cell is 379 pm,what is the radius of a rhodium atom in picometers?

A) 134 pm
B) 536 pm
C) 1070 pm
D) 309 pm
E) 47.4 pm

Question 9

In any cubic lattice an atom lying at the face of a unit cell is shared equally by how many unit cells?

A) 2
B) 1
C) 4
D) 8
E) 6

Question 10

Niobium crystallizes in a body-centered cubic lattice.If the radius of niobium is 146 pm,what is the unit cell edge length?

A) 337 pm
B) 292 pm
C) 195 pm
D) 146 pm
E) 63.2 pm

Question 11

Which of the following statements concerning the cubic unit cell is/are CORRECT?
1)For cubic unit cells,three cell symmetries occur: primitive cubic,face-centered cubic,and body-centered cubic.
2)The cell edges of a cubic unit cell are all equal in length.
3)The corner angles of a cubic cell are 90 ^$\circ$ .

A) 1 only
B) 2 only
C) 3 only
D) 2 and 3
E) 1,2,and 3

Question 12

Which of the following statements concerning a metal crystallized in a face-centered cubic cell is/are CORRECT?
1)One metal atom is located on each face of the unit cell,where it is shared equally between four unit cells.
2)One metal atom is located at the center of the unit cell.
3)A metal atom is located at each of the eight lattice points,where it is shared equally between eight unit cells.

A) 1 only
B) 2 only
C) 3 only
D) 1 and 3
E) 1,2 and 3

Question 13

What is the distance,in atomic radii,across a diagonal face of a face-centered unit cell?

A)
B) 2 $\times$ r
C) 4 $\times$ r
D)
E) r

Question 14

Polonium (atomic mass 209.0 g/mol)crystallizes in a primitive cubic unit cell.If the density of polonium is 9.15 g/cm³,what is the radius of a polonium atom (in pm)?

A) 168 pm
B) 238 pm
C) 336 pm
D) 475 pm
E) 672 pm

Question 15

Gold crystallizes in a face-centered cubic lattice with an edge length of 407.8 pm.What is the density of gold?

A) 1.21 g/cm³
B) 4.82 g/cm³
C) 2.41 g/cm³
D) 9.65 g/cm³
E) 19.3 g/cm³

Question 16

If a metal crystallizes in a body-centered cubic lattice,each metal atom has ____ "nearest neighbors."

A) 3
B) 4
C) 6
D) 8
E) 12

Question 17

Arrange the three common unit cells in order from least dense to most dense packing.

A) face-centered cubic < body-centered cubic < primitive cubic
B) primitive cubic < body-centered cubic < face-centered cubic
C) primitive cubic < face-centered cubic < body-centered cubic
D) body-centered cubic < primitive cubic < face-centered cubic
E) body-centered cubic < face-centered cubic < primitive cubic

Question 18

Which of the following concerning the 2-D lattice provided below is/are correct?
1)One possible unit cell contains a single A and a single $\bullet$ .
2)More than one unit cell which reproduces this lattice is possible.
3)One possible unit cell contains four A's and four $\bullet$ 's.

A) 1 only
B) 2 only
C) 3 only
D) 1 and 2
E) 1,2,and 3

Question 19

Which equation represents the number of atoms in a body-centered cubic unit cell?

A)
B)
C)
D)
E)

Question 20

The space-filling representation provided below is an example of a _____ unit cell,which contains _____ atom(s).

A) primitive cubic,1 atom
B) body centered cubic,2 atoms
C) face centered cubic,4 atoms
D) primitive cubic,8 atoms
E) body centered cubic,3 atoms

Question 21

Copper crystallizes in a face-centered cubic lattice.The radius of a copper atom is 128 pm.What is the edge length of the unit cell?

A) 362 pm
B) 256 pm
C) 512 pm
D) 272 pm
E) 128 pm

Question 22

If an ionic solid has a face-centered cubic lattice of anions (X^n-)and all the octahedral holes are occupied by metal cations (M^m+),what is the formula for the compound?

A) M₂X
B) MX
C) MX₂
D) M₂X₃
E) M₃X₂

Question 23

What is the $\underline{\text{simplest }}$ formula of the compound represented by the unit cell provided below?

A) AB
B) AB₂
C) AB₃
D) A₂B₃
E) A₂B₄

Question 24

A metal crystallizes in a face-centered cubic lattice.The radius of the atom is 125 pm and the density of the element is 8.91 g/cm³.What is the identity of the metal?

A) Yb
B) Cu
C) Ca
D) Sr
E) Ni

Question 25

Calcium crystallizes in a face-centered cubic lattice.The density of the calcium is 1.55 g/cm³.What is the volume of a single unit cell?

A) cm³
B) cm³
C) cm³
D) cm³
E) cm³

Question 26

Rubidium iodide (molar mass 212.4 g/mol)has a face-centered cubic unit cell with rubidium ions in octahedral holes.If the radius of iodide ion is 219 pm and the density of RbI is 3.55 g/cm³,what is the radius of the rubidium ion (in pm)?

A) 112 pm
B) 149 pm
C) 181 pm
D) 297 pm
E) 419 pm

Question 27

The metal potassium crystallizes in a body-centered cubic lattice.If the density of potassium is 0.856 g/cm³,what is the unit cell volume?

A) 3.88 $\times$ 10⁶ pm³
B) 3.64 $\times$ 10⁴ pm³
C) 1.52 $\times$ 10⁸ pm³
D) 7.59 $\times$ 10⁷ pm³
E) 7.27 $\times$ 10⁴ pm³

Question 28

Lithium chloride crystallizes in a face-centered cubic unit cell with chloride ions occupying the lattice points and lithium ions occupying octahedral holes.How many chloride ions surround each lithium ion in LiCl?

A) 1
B) 4
C) 6
D) 8
E) 12

Question 29

The metal barium crystallizes in a body-centered cubic lattice.If the density of barium is 3.51 g/cm³,what is the atomic radius of barium?

A) 15.1 pm
B) 174 pm
C) 42.5 pm
D) 19.0 pm
E) 219 pm

Question 30

Chromium (atomic mass 52.00 g/mol)crystallizes in a body-centered cubic unit cell.If the length of an edge of the unit cell is 289 pm,what is the density (in g/cm³)of chromium?

A) 3.58 g/cm³
B) 7.15 g/cm³
C) 13.7 g/cm³
D) 14.3 g/cm³
E) 21.3 g/cm³

Question 31

Calcium sulfide has a face-centered cubic unit cell with calcium ions in octahedral holes.How many ions of each element are contained in each unit cell?

A) 1 calcium ions; 1 sulfide ions
B) 2 calcium ions; 2 sulfide ions
C) 2 calcium ions; 4 sulfide ions
D) 4 calcium ions; 2 sulfide ions
E) 4 calcium ions; 4 sulfide ions

Question 32

A metal crystallizes in a face-centered cubic lattice.The radius of the atom is 214 pm and the density of the element is 2.63 g/cm³.What is the volume of the unit cell?

A) 4.11 $\times$ 10⁷ pm³
B) 3.80 $\times$ 10⁹ pm³
C) 2.22 $\times$ 10⁸ pm³
D) 9.80 $\times$ 10⁶ pm³
E) 1.64 $\times$ 10⁸ pm³

Question 33

Calcium oxide has a face centered cubic unit cell of oxide ions with the calcium in octahedral holes.If the radius of Ca²⁺ is 106 pm and the density of CaO is 3.34 g/cm³,what is the radius of the oxide ion? (100 cm = 1 $\times$ 10¹² pm)

A) 160 pm
B) 120 pm
C) 106 pm
D) 135 pm
E) 269 pm

Question 34

Magnesium sulfide (molar mass 56.37 g/mol)has a face-centered cubic unit cell with magnesium ions in octahedral holes.The ionic radii of magnesium ions and sulfide ions are 79 pm and 184 pm,respectively.What is the density of MgS (in g/cm³)?

A) 1.29 g/cm³
B) 2.57 g/cm³
C) 3.64 g/cm³
D) 5.15 g/cm³
E) 7.28 g/cm³

Question 35

In what type of unit cell are the "A" atoms arranged in the unit cell provided? 2

A) primitive cubic
B) body-centered cubic
C) face-centered cubic

Question 36

Which of the following statements is/are CORRECT? If an ionic compound with the formula MX forms a face-centered cubic unit cell with the anions (X^n-)at the lattice points,the cations (Mⁿ⁺)may occupy
1)one fourth of the tetrahedral holes in each unit cell.
2)all of the octahedral holes in each unit cell.
3)the center of each face in each unit cell.

A) 1 only
B) 2 only
C) 3 only
D) 1 and 2
E) 1,2,and 3

Question 37

If an ionic compound with the formula MX₂ forms a face-centered cubic unit cell with the cations (M²ⁿ⁺)at the lattice points,the anions (X^n-)will occupy

A) all of the tetrahedral holes in each unit cell.
B) half of the tetrahedral holes in each unit cell.
C) all of the octahedral holes in each unit cell.
D) the center of each face in each unit cell.
E) the cubic hole in the center of the each unit cell.

Question 38

The metal chromium crystallizes in a body-centered cubic lattice.If the density of chromium is 7.14 g/cm³,what is the unit cell edge length?

A) 289 pm
B) 77.0 pm
C) 77.5 pm
D) 61.1 pm
E) 230 pm

Question 39

If an ionic compound with the formula MX forms a primitive cubic unit cell with the anions (X^n-)at the lattice points,the cations (M²ⁿ⁺)will occupy

A) all of the tetrahedral holes in each unit cell.
B) half of the tetrahedral holes in each unit cell.
C) the cubic hole in the center of the each unit cell.
D) the center of each face in each unit cell.
E) all of the octahedral holes in each unit cell.

Question 40

Cesium bromide crystallizes in a primitive cubic unit cell with bromide ions at the lattice points.The cesium ions occupy cubic holes.How many bromide ions surround each cesium ion in cesium bromide?

A) 1
B) 2
C) 4
D) 8
E) 12

Question 41

Which of the following is/are physical properties of amorphous solids?
1)Amorphous solids have well defined melting points.
2)At the particulate level,amorphous solids do not have long range order.
3)Polymeric materials never form amorphous solids.

A) 1 only
B) 2 only
C) 3 only
D) 1 and 3
E) 2 and 3

Question 42

In metals,there are not enough electrons to fill all of the electronic energy levels.At 0 K,the highest energy level filled is referred to as the ________.

A) valence band
B) conduction band
C) free energy
D) Fermi level
E) band gap

Question 43

Which of the following statements concerning semiconductors is/are CORRECT?
1)The conduction of electricity in p-type semiconductors occurs by the movement of electrons in the conduction band.
2)Doping an intrinsic semiconductor,such as silicon,with a Group 3A element will produce a p-type semiconductor.
3)An n-type semiconductor uses the movement of positive holes in the valence band to conduct electricity.

A) 1 only
B) 2 only
C) 3 only
D) 1 and 2
E) 1,2 and 3

Question 44

Which of the compounds below is not an example of a molecular solid?

A) I₂(s)
B) SiO₂(s)
C) CO₂(s)
D) H₂O(s)
E) C₂₅H₅₂(s)

Question 45

The lattice energy of NaBr(s)is -751 kJmol.Use this value and the following thermochemical data to determine the electron attachment enthalpy of Br(g). $\Delta$ IE is the enthalpy of ionization.

A) -1827 kJ/mol
B) -397 kJ/mol
C) -325 kJ/mol
D) +325 kJ/mol
E) +397 kJ/mol

Question 46

Strontium oxide has a face centered cubic unit cell of oxide ions with the strontium in octahedral holes.The radius of Sr²⁺ is 127 pm and the radius of O^2- is 135 pm.What is the density of strontium oxide? (100 cm = 1 $\times$ 10¹² pm)

A) 0.209 g/cm³
B) 1.20 g/cm³
C) 2.39 g/cm³
D) 3.59 g/cm³
E) 4.78 g/cm³

Question 47

Which one of the following elements is considered a semiconductor?

A) Li
B) Fe
C) Cl
D) Ni
E) Si

Question 48

The bandgap of Si is 107.1 kJ/mol.What is the maximum wavelength of light that can excite an electron transition across the band gap? (h = 6.626 $\times$ 10^-34 J.s; c = 3.000 $\times$ 10⁸ m/s)

A) 551.4 nm
B) 1118 nm
C) 549.0 nm
D) 1852 nm
E) 516.9 nm

Question 49

Which of the following might be used as a dopant in a silicon host to create a p-type semiconductor?

A) Al
B) P
C) As
D) S
E) Ge

Question 50

Which of the following compounds is expected to have the strongest ionic bonds?

A) MgO
B) KBr
C) NaI
D) BaO
E) SrS

Question 51

Which of the following compounds is expected to have the strongest ionic bonds?

A) RbI
B) KCl
C) NaBr
D) CsF
E) LiF

Question 52

Silver chloride crystallizes with the sodium chloride (rock salt)structure.The length of a unit cell edge is 555 pm.What is the density of AgCl?

A) 5.57 g/cm³
B) 4.19 g/cm³
C) 2.79 g/cm³
D) 2.10 g/cm³
E) 1.39 g/cm³

Question 53

Calculate the lattice energy of NaBr(s),given the following thermochemical equations,where $\Delta$ IE and $\Delta$ EA are enthalpy of ionization and electron attachment enthalpy,respectively.

A) -1401 kJ
B) -751 kJ
C) -241 kJ
D) +241 kJ
E) +751 kJ

Question 54

Lattice enthalpy may be calculated using the thermodynamic relationship known as

A) the Clausius-Clapeyron equation.
B) the Born-Haber cycle.
C) the dynamic equilibrium expression.
D) Avogadro's hypothesis.
E) cubic cell enthalpy of formation equation.

Question 55

Iron(II)sulfide has a primitive cubic unit cell with sulfide ions at the lattice points.The ionic radii of iron(II)ions and sulfide ions are 88 pm and 184 pm,respectively.What is the density of FeS (in g/cm³)?

A) 2.56 g/cm³
B) 4.71 g/cm³
C) 5.25 g/cm³
D) 6.66 g/cm³
E) 8.97 g/cm³

Question 56

Using the thermodynamic data below,and a value of -717 kJ/mole for the lattice enthalpy for KCl,calculate the ionization energy of K.

A) -576 kJ/mol
B) +141 kJ/mol
C) +419 kJ/mol
D) +576 kJ/mol
E) +597 kJ/mol

Question 57

Elements that have their highest energy electrons in a $\textbf{ filled }$ band of molecular orbitals that is separated from the lowest empty band by an energy difference much too large for electrons to jump between bands are called ____.

A) semiconductors
B) metals
C) conductors
D) insulators
E) isomorphs

Question 58

Which two of the following materials are most likely to be amorphous solids: water,nylon,glass,potassium nitrate?

A) water and glass
B) nylon and aspirin
C) water and nylon
D) water and aspirin
E) nylon and glass

Question 59

Which of the following is expected to have the most negative lattice enthalpy?

A) LiCl
B) NaCl
C) KCl
D) RbCl
E) CsCl

Question 60

The lattice energy of NaBr is -752 kJ/mol.This energy corresponds to which reaction below?

A) Na(s)+ 1/2 Br₂(g) $\to$ NaBr(s)
B) Na(g)+ Br(g) $\to$ NaBr(s)
C) Na(g) + Br(g) $\to$ NaBr(s)
D) Na⁺(g)+ Br^-(g) $\to$ NaBr(s)
E) Na⁺(aq)+ Br^-(aq) $\to$ NaBr(s)

Question 61

Which of the statements concerning the phase diagram is/are CORRECT?
1)Only the solid phase exists at point A.
2)At point C,the solid and liquid phases are in equilibrium.
3)At point D,the critical point,the substance exists as a supercritical fluid.

A) 1 only
B) 2 only
C) 3 only
D) 1 and 3
E) 1,2,and 3

Question 62

A salt with a 1:1 ratio of anions to cations may pack in a face-centered cubic unit cell with the anions at the lattice points and the cations occupying one-half of the ________ holes.Zinc sulfide is an example of this structure.

Question 63

Given the accompanying phase diagram,under what conditions will liquid be found in equilibrium with either solid or gas?

A) Anywhere along curve AB.
B) Anywhere along curve AC.
C) Anywhere along curve AD.
D) Anywhere along curve AB and AC.
E) Anywhere along curve AB and AD.

Question 64

What process occurs when the temperature of a substance at Point A is increased (at constant pressure)until the substance is at Point B?

A) condensation
B) vaporization
C) sublimation
D) melting
E) freezing

Question 65

An unknown white solid was found to have a melting point of 150^oC.It is soluble in
Water,but it is a poor conductor in aqueous solution.Which of the following substances
Is the most likely?

A) C₆H₁₂O₆ (glucose)
B) KCl
C) Rb
D) C (diamond)
E) Si

Question 66

A low melting solid readily dissolves in water to give a nonconducting solution.The solid is most likely a ___.

A) molecular solid
B) ionic solid
C) covalent network solid
D) weak base
E) metallic solid

Question 67

Which one of the following substances is $\textbf{ incorrectly }$ matched with the kind of solid it forms?
$\underline{\text{ Substance }}$ / $\underline{\text{ Kind of Solid }}$

A) sulfur dioxide / molecular
B) graphite / covalent
C) calcium bromide / ionic
D) potassium / ionic
E) methane / molecular

Question 68

Which of the following ionic compounds is expected to have the lowest enthalpy of fusion?

A) RbF
B) RbCl
C) RbBr
D) RbI

Question 69

Above a substance's ________ temperature,it is not possible to compress the substance into the liquid phase.If enough pressure is applied the substance will become a supercritical fluid.

Question 70

Which process requires the greatest endothermic change in enthalpy for water?

A) freezing
B) condensation
C) sublimation
D) melting
E) vaporization

Question 71

A sketch of a phase diagram is given below. Which statement about this diagram is $\underline{\text{ not true? }}$

A) Increasing pressure at constant temperature can melt the solid.
B) Increasing temperature at constant pressure can cause the solid to sublime.
C) Increasing temperature at constant pressure can cause the liquid to vaporize.
D) Increasing pressure at constant temperature can cause deposition of solid from gas.
E) Increasing pressure at constant temperature can cause liquid to freeze.

Question 72

A phase diagram of a pure compound has a triple point at 22.0 ^$\circ$ C and 32 mm Hg,a normal melting point at 22.8 ^$\circ$ C,and a normal boiling point at 107 ^$\circ$ C.Which of the following statements regarding this compound is/are CORRECT?
1)The density of the liquid is greater than that of the solid.
2)Sublimation occurs if starting with a solid at a constant temperature of 25 ^$\circ$ C the pressure is decreased until a phase change occurs.
3)Condensation occurs if the temperature is decreased from 122 ^$\circ$ C to 75 ^$\circ$ C at a constant pressure of 1.00 atm.

A) 1 only
B) 2 only
C) 3 only
D) 1 and 2
E) 1,2,and 3

Question 73

If a pure substance begins at point C on the phase diagram below and the pressure on the substance is increased until point B is reached,what process occurs?

A) fusion
B) vaporization
C) condensation
D) sublimation
E) none of these

Question 74

The phase diagram for CO₂ has a triple point at -56.6 ^$\circ$ C and 5.19 atm,and a critical point at 31.0 ^$\circ$ C and 73 atm.The solid and gas phases are in equilibrium at -78.7 ^$\circ$ C and 1.00 atm.Which of the following statements regarding CO₂ is/are CORRECT?
1)Sublimation occurs if the temperature of the solid phase is increased from -79.0 ^$\circ$ C to 0.0 ^$\circ$ C at a constant pressure of 2.5 atm.
2)CO₂ is a supercritical fluid at 55 ^$\circ$ C and 75 atm.
3)At pressures greater than its critical pressure (73 atm),CO₂ will not exist as a solid at any temperature.

A) 1 only
B) 2 only
C) 3 only
D) 1 and 2
E) 1,2,and 3

Question 75

Sodium chloride crystallizes in a(n)________ cubic unit cell with chloride ions occupying the lattice points.The sodium ions occupy interstitial regions,with each cation in contact with six chloride ions.

Question 76

On the phase diagram below,which point corresponds to conditions where solid,liquid,and gas phases all exist?

A) B
B) C
C) D
D) E
E) G

Question 77

Point D on the phase diagram is referred to as the ________ point.

A) triple
B) normal boiling
C) critical
D) normal freezing
E) divergent