Select the correct formula for a compound formed from calcium and chlorine.

A) CaCl B) CaCl₂ C) Ca₂Cl D) Ca₂Cl₂ E) CaCl₃

b

Select the correct formula for a compound formed from barium and nitrogen.

A) BaN B) BaN₂ C) Ba₂N₃ D) Ba₂N E) Ba₃N₂

e

The diameter of a chloride ion is 362 pm, and the diameter of a potassium ion is 276 pm. What is the distance between the nuclei of adjacent chloride and potassium ions in solid potassium chloride?

A) 1276 pm B) 638 pm C) 319 pm D) 181 pm E) 138 pm

c

The lattice energy for ionic crystals increases as the charge on the ions _____________ and the size of the ions __________________.

A)

increases, increases

B)

increases, decreases

C)

decreases, increases

D)

decreases, decreases

E)

None of the above is generally correct.

b

Select the compound with the highest (i.e., most negative) lattice energy.

A) CaS(s) B) BaO(s) C) NaI(s) D) LiBr(s) E) MgO(s)

e

Select the compound with the lowest (i.e., least negative) lattice energy.

A) CsBr(s) B) NaCl(s) C) SrO(s) D) CaO(s) E) KBr(s)

a

The lattice energy of MgCl₂ is the energy change for which one of the following processes?

A)Mg(s) + Cl₂(g) ® MgCl₂(s)

D)Mg²⁺(g) + 2Cl^–(g) ® MgCl₂(s)

B)Mg(g) + 2Cl(g) ® MgCl₂(s)

E)MgCl₂(aq) ® MgCl₂(s)

C)Mg²⁺(s) + 2Cl^–(g) ® gCl₂(g)

d

Analysis of an unknown substance showed that it has a high boiling point and is brittle. It is an insulator as a solid but conducts electricity when melted. Which of the following substances would have those characteristics?

A) HCl B) Al C) KBr D) SiF₄ E) I₂

c

When two atoms form a covalently-bonded diatomic molecule, the distance between the nuclei at which the potential energy is at a minimum is called

A)the bond energy.

D)the covalent radius.

B)the bond length.

E)the covalent diameter.

C)the molecular diameter.

b

Arrange the following bonds in order of increasing bond strength.

A)C–I < C–Br < C–Cl < C–F

D)C–I < C–Br < C–F< C–Cl

B)C–F < C–Cl < C–Br < C–I

E)None of the above orders is correct.

C)C–Br < C–I < C–Cl < C–F

a

Select the strongest bond in the following group.

A) C–S B) C–O C) C=C D) CºN E) C–F

d

Nitrogen and hydrogen combine to form ammonia in the Haber process. Calculate (in kJ) the standard enthalpy change DH° for the reaction written below, using the bond energies given.

N₂(g) + 3H₂(g) ® 2NH₃(g)

Bond:

NºN

H–H

N–H

Bond energy (kJ/mol):

945

432

391

A) –969 kJ B) –204 kJ C) –105 kJ D) 204 kJ E) 595 kJ

c

Acetone can be easily converted to isopropyl alcohol by addition of hydrogen to the carbon–oxygen double bond. Calculate the enthalpy of reaction using the bond energies given.

Bond:

C=O

H–H

C–H

O–H

C–C

C–O

Bond energy (kJ/mol):

745

436

414

464

347

351

A) –484 kJ B) –366 kJ C) –48 kJ D) +48 kJ E) +366 kJ

c

Electronegativity is a measure of

A)

the energy needed to remove an electron from an atom.

B)

the energy released when an electron is added to an atom.

C)

the magnitude of the negative charge on an electron.

D)

the attraction by an atom for electrons in a chemical bond.

E)

the magnitude of the negative charge on a molecule.

d

Which of the following elements is the most electronegative?

A) S B) Ru C) Si D) Te E) Cs

a

Arrange aluminum, nitrogen, phosphorus, and indium in order of increasing electronegativity.

A)Al < In < N < P

D)In < P < Al < N

B)Al < In < P < N

E)None of the above orders is correct.

C)In < Al < P < N

c

Based on electronegativity trends in the periodic table, predict which of the following compounds will have the greatest % ionic character in its bonds.

A) H₂O B) LiI C) CaO D) RbF E) HCl

d

Select the most polar bond amongst the following.

A) C–O B) Si–F C) Cl–F D) C–F E) C–I

b