Deck 9: Solids

Question 1

Which of the following types of solids represents the most ordered arrangement of repeating units?

A) polycrystalline
B) crystalline
C) hydrophobic
D) amorphous
E) none of these

Answer 1

crystalline

Question 2

Diamond is an example of:

A) a molecular solid
B) a network covalent solid
C) an ionic solid
D) a solid solution
E) a metallic solid

Answer 2

a network covalent solid

Question 3

SiO₂ is a network covalent solid. Which of the following is most likely to be true of SiO₂?

A) SiO₂ would have a low melting point and would conduct electricity when melted.
B) SiO₂ would conduct electricity as a solid and its melting point cannot be predicted.
C) SiO₂ would have a high melting point and would conduct electricity when melted.
D) SiO₂ would have a high melting point and wouldn't conduct electricity when melted.
E) SiO₂ would have a low melting point and wouldn't conduct electricity when melted.

Answer 3

SiO₂ would have a high melting point and wouldn't conduct electricity when melted.

Question 4

Which of the following types of solids is most likely to be soft, have a low melting point, and not conduct electricity when melted?

A) ionic
B) molecular
C) network covalent
D) metallic
E) none of the above

Question 5

Which solid is held together by an extended network of covalent bonds?

A) sodium chloride
B) gold
C) calcium carbonate
D) diamond
E) dry ice (solid CO₂)

Question 6

Which force makes the most important contribution to the lattice energy of solid CO₂?

A) metallic bonding
B) ionic bonding
C) hydrogen bonding
D) dispersion forces
E) all of the above

Question 7

Diamond (C(s)) is a network covalent solid. Which of the following is most likely to be true of diamond?

A) Diamond would have a low melting point and would conduct electricity when melted.
B) Diamond would conduct electricity as a solid and its melting point cannot be predicted.
C) Diamond would have a high melting point and would conduct electricity when melted.
D) Diamond would have a high melting point and wouldn't conduct electricity when melted.
E) Diamond would have a low melting point and wouldn't conduct electricity when melted.

Question 8

A compound that is a poor conductor of electricity when solid, but a very good conductor when molten is most likely to fit into which category?

A) molecular solid
B) covalent solid
C) ionic solid
D) metallic solid
E) any of the above

Question 9

Arrange the following ionic compounds in order of increasing lattice energy (energy to break the solid into its gaseous ions).

MgF₂, SrF₂, BeF₂

A) MgF₂ < SrF₂ < BeF₂
B) SrF₂ < MgF₂ < BeF₂
C) MgF₂ < BeF₂ < SrF₂
D) SrF₂ < BeF₂ < MgF₂
E) BeF₂ < MgF₂ < SrF₂

Question 10

Use the bond-type triangle for


-Which of the following compounds will have the most ionic character?

A) AlSb
B) AlN
C) AlLi
D) AlP
E) AlAs

Question 11

Use the bond-type triangle for


-Which of the following compounds will have the most covalent character?

A) NaCl
B) SrCl₂
C) PCl₃
D) AlCl₃
E) SnCl₄

Question 12

Use the bond-type triangle for


-Which of the following compounds will have the most metallic character?

A) SnBr₄
B) SnO₂
C) SnP
D) SnS
E) SnCl₄

Question 13

Use the bond-type triangle for


-Predict which compound has a high melting point and is a conductor in the molten and aqueous state.

A) AlSb
B) AlN
C) AlLi
D) AlP
E) AlAs

Question 14

Use the bond-type triangle for


-Predict which compound is an electrical insulator and has a relatively low melting point.

A) NaIn
B) SrCl₂
C) PCl₃
D) AlCl₃
E) CaH₂

Question 15

Use the bond-type triangle for


-Predict which solid is the best electrical conductor.

A) SnBr₄
B) SnO₂
C) SnP
D) SnS
E) SnCl₄

Question 16

Use the bond-type triangle for


-Predict which compound is an insulating ceramic material.

A) MgZn₂
B) Li₃P
C) Li₂O
D) LiCl
E) GaAs

Question 17

Which of the following structures has a coordination number of six?

A) simple cubic
B) body-centered cubic
C) cubic closest packed
D) hexagonal closest packed
E) none of the above

Question 18

Which of the following correctly describes a body-centered cubic structure?

A) Coordination Number = 6, 1 atom per unit cell
B) Coordination Number = 6, 2 atoms per unit cell
C) Coordination Number = 6, 4 atoms per unit cell
D) Coordination Number = 8, 1 atom per unit cell
E) Coordination Number = 8, 2 atoms per unit cell

Question 19

What is the ratio of the length of the body diagonal of a cube to the face diagonal of the cube?

A) 0.817
B) 1.00
C) 1.22
D) 1.41
E) 1.73

Question 20

What is the relationship between the unit cell edge length (a) and the radius of a metal atom (r) when the metal crystallizes in a face-centered cubic unit cell?

A) r = a
B) r = ( a)/4
C) r = ( a)/2
D)r = ( a)/4
E) none of the above

Question 21

Calcium titanate crystallizes in a cubic unit cell with titanium atoms at the corners of the cell, oxygen atoms in the middle of the faces of the cell, and a calcium atom in the center of the cell. What is the formula of calcium titanate?

A) CaTiO
B) CaTiO₃
C) CaTiO₄
D) Ca₂TiO₄
E) CaTi₈O₂

Question 22

Calculate the number of chloride and ammonium ions per unit cell if NH₄Cl is a simple cubic unit cell of NH₄⁺ ions with a Cl^- ion in the center of the unit cell.

A) 1 NH₄⁺ ion and 1 Cl^- ion
B) 2 NH₄⁺ ions and 2 Cl^- ions
C) 4 NH₄⁺ ions and 4 Cl^- ions
D) 8 NH₄⁺ ions and 8 Cl^- ions
E) none of the above

Question 23

What is the density in g/cm³ of sodium if this metal crystallizes in a body-centered cubic unit cell with a cell edge of 0.429 nm?

A) 0.484 g/cm³
B) 0.582 g/cm³
C) 0.967 g/cm³
D) 1.94 g/cm³
E) 9.67 x 10^-25 g/cm³

Question 24

What is the approximate density in g/cm³ of titanium metal if the atomic radius of a titanium atom is 0.145 nm and the atoms form a body-centered cubic unit cell?

A) 0.1 g/cm³
B) 1 g/cm³
C) 5 g/cm³
D) 25 g/cm³
E) 30 g/cm³

Question 25

Tungsten crystallizes in a cubic unit cell with a cell edge of 0.3981 nm. The density of tungsten is 19.35 g/cm³. Calculate the number of atoms per unit cell.

A) 1
B) 2
C) 3
D) 4
E) 8

Question 26

Iron crystallizes in a cubic unit cell with a cell edge of 0.2866 nm. The density of iron is 7.875 g/cm³. Calculate the number of atoms per unit cell.

A) 1
B) 2
C) 3
D) 4
E) 8

Question 27

Calculate the metallic radius in nanometers of the Ag atom if silver crystallizes in a face-centered cubic unit cell with a cell edge of 0.4086 nm.

Question 28

Cesium iodide consists of a simple cubic lattice of l^- ions with Cs⁺ ions in the center of the cubes. If the cell edge length is 0.445 nm, what is the Cs-I interatomic distance in nanometers?

A) 0.193 nm
B) 0.314 nm
C) 0.385 nm
D) 0.629 nm
E) 0.770 nm

Question 29

In KF, the K⁺ and F^- ions are almost exactly the same size: 0.134 nm. Which would be larger: a neutral potassium atom or a neutral fluorine atom?

Question 30

Which of the following would be the correct order from lowest melting point to highest for the following substances?

A) NaF < C₃H₈ < CH₃CH₂OH
B) C₃H₈ < NaF < CH₃CH₂OH
C) C₃H₈ < CH₃CH₂OH < NaF
D) CH₃CH₂OH < C₃H₈ < NaF
E) none of these

Question 31

When diamond, NaCl, and water are boiled, the bonds being broken can best be described respectively as:

A) covalent, ionic, covalent
B) ionic, covalent, hydrogen bonds
C) covalent, ionic, hydrogen bonds
D) hydrogen bonds, ionic, covalent
E) none of the above