Question 1

Given the bond enthalpies N-H (389) , Cl-Cl (243) , N-Cl (201) , and H-Cl (431)  in kJ/mol, compute ΔH° in kJ/mol for NH3(g)  + Cl2(g)  → NH2Cl + HCl(g)

Accepted Answer

A)   -393
B)   -1100
C)   +71
D)   +393
E)   0F) A) and D)
G) A) and E) E

Question 2

What is the bond order for the carbon-oxygen bond in formaldehyde (CH2O) , which has no O-H bonds?

Accepted Answer

A)   0
B)   1
C)   2
D)   3
E)   4F) B) and D)
G) A) and E)

Question 3

Which of the following molecules has both an electron group geometry and a molecular geometry described as trigonal planar?

Accepted Answer

A)   SiH4
B)   PF3
C)   OF2
D)   CHF3
E)   BF3F) None of the above
G) A) and D) E

Question 4

What is the molecular shape of BrF5?

Accepted Answer

A)   linear
B)   square pyramid
C)   square planar
D)   octahedral
E)   trigonal bipyramidF) A) and B)
G) C) and E)

Question 5

After drawing the Lewis dot structure for BeCl2, determine the number of single bonds, double bonds, and lone pairs on the central atom.

Accepted Answer

A)   2, 0, 0
B)   2, 0, 2
C)   2, 0,1
D)   0, 2, 0
E)   1, 1, 0F) A) and B)
G) A) and E)

Question 6

How many "dots" should be shown for the oxygen symbol in lithium oxide?

Accepted Answer

A)   2
B)   4
C)   6
D)   8
E)   10F) A) and E)
G) A) and D)

Question 7

Choose the INCORRECT statement.

Accepted Answer

A)   In a Lewis structure, a terminal atom is bonded to two or more atoms.
B)   In a Lewis structure all valence electrons must appear.
C)   In a Lewis structure, usually all electrons are paired.
D)   In a Lewis structure, usually each atom acquires an outer-shell octet of electrons; H has 2 outer shell electrons.
E)   In Lewis structures, most multiple covalent bonds are formed by C, N, O, P, and S.F) A) and E)
G) A) and B)

Question 8

After drawing the Lewis dot structure for XeCl2, determine the number of single bonds, double bonds, and lone pairs on the central atom.

Accepted Answer

A)   2, 0, 2
B)   0, 2, 0
C)   0, 2, 1
D)   2, 0, 3
E)   2, 0, 0F) A) and D)
G) B) and D)

Question 9

A chemical bond for which one of the bonded atoms provides both electrons for the bond is referred to as a:

Accepted Answer

A)   double covalent bond
B)   coordinate covalent bond
C)   formal covalent bond
D)   free radical bond
E)   VSEPR bondF) A) and B)
G) B) and C) B

Question 10

Given the following bond lengths in pm: C-C, 154; C = C, 134; Cl - Cl, 199 What is the best estimate of the C-Cl bond length in CCl4 in pm?

Accepted Answer

A)   353 pm
B)   706 pm
C)   167 pm
D)   333 pm
E)   177 pmF) A) and E)
G) B) and D)

Question 11

Given the listed average bond energies, calculate the enthalpy change for the production of 48 g of methanol by the reaction: CO2(g)  + 3 H2(g)  → CH3OH(g)  + H2O(g) 
C-O/360 kJ/mol C=O/736 kJ/mol H-H/436 kJ/mol
H-O/464 kJ/mol H-C/414 kJ/mol

Accepted Answer

A)   +214 kJ
B)   +639 kJ
C)   0
D)   -214 kJ
E)   -108 kJF) A) and C)
G) None of the above

Question 12

Which of the following species exhibits resonance?

Accepted Answer

A)   OF2
B)   ClO3-
C)   N2
D)   PCl5
E)   BrF3F) A) and C)
G) B) and D)

Question 13

With the representations of "I" for ionic bond, "PC" for polar covalent bond, and "NP" for nonpolar covalent bond, which of the following descriptive combinations is correct?

Accepted Answer

A)   CsF/PC
B)   F2/I
C)   NO/NP
D)   HCl/PC
E)   BrCl/NPF) A) and C)
G) All of the above

Question 14

What is the correct molecular geometry for the carbon atom in urea (NH2) 2CO?

Accepted Answer

A)   Tetrahedral
B)   T-Shaped
C)   Trigonal planar
D)   Trigonal pyramidal
E)   Trigonal bipyramidalF) C) and E)
G) C) and D)

Question 15

Choose the INCORRECT statement.

Accepted Answer

A)   In a Lewis structure, a covalent bond can be represented by a pair of electrons or a dash.
B)   Pairs of electrons not involved in bonding are called lone pairs.
C)   A molecule of two atoms is called a diatomic molecule.
D)   Two electrons involved in a bond produce a double bond.
E)   Three electron pairs involved in a bond produce a triple bond.F) A) and E)
G) A) and D)

Question 16

Given the bond enthalpies N≡N (946) , H-H (436) , H-N (389) , all in kJ/mol, estimate ΔH for the following reaction: N2(g)  + 3 H2(g)  → 2NH3(g) .

Accepted Answer

A)   -215 kJ
B)   -863 kJ
C)   -80 kJ
D)   568 kJ
E)   -1476 kJF) A) and D)
G) B) and C)

Question 17

Which of the following species has a pyramidal structure?

Accepted Answer

A)   ClO3-
B)   ClO4-
C)   ClO2-
D)   ClO2E) All of the above
F) C) and D)

Question 18

Which chloride should have the greatest covalent character?

Accepted Answer

A)   NaCl
B)   BeCl2
C)   KCl
D)   BaCl2
E)   CaCl2F) A) and E)
G) C) and E)

Question 19

Choose the INCORRECT statement.

Accepted Answer

A)   A Lewis symbol consists of a chemical symbol and the outer shell electrons.
B)   In a Lewis symbol, the chemical symbol represents the nucleus of the atom.
C)   A Lewis structure is a combination of Lewis symbols that represent the transfer or sharing of electrons in a chemical bond.
D)   An ion written as a Lewis symbol has brackets outside the electrons.
E)   An ion written as a Lewis symbol has the charge written as a superscript outside the closing bracket.F) B) and E)
G) None of the above

Question 20

Which of the following species is best represented by a resonance hybrid having two contributing structures?

Accepted Answer

A)   nitric acid
B)   nitrous acid
C)   nitride ion
D)   nitrate ion
E)   nitrogenF) B) and E)
G) D) and E)

Exam 10: Chemical Bonding I: Basic Concepts

Given the bond enthalpies N-H (389) , Cl-Cl (243) , N-Cl (201) , and H-Cl (431) in kJ/mol, compute ΔH° in kJ/mol for NH3(g) + Cl2(g) → NH2Cl + HCl(g)

Correct AnswerverifiedE

What is the bond order for the carbon-oxygen bond in formaldehyde (CH2O) , which has no O-H bonds?

Correct AnswerverifiedShow Answer

Which of the following molecules has both an electron group geometry and a molecular geometry described as trigonal planar?

Correct AnswerverifiedE

What is the molecular shape of BrF5?

Correct AnswerverifiedShow Answer

After drawing the Lewis dot structure for BeCl2, determine the number of single bonds, double bonds, and lone pairs on the central atom.

Correct AnswerverifiedShow Answer

How many "dots" should be shown for the oxygen symbol in lithium oxide?

Correct AnswerverifiedShow Answer

Choose the INCORRECT statement.

Correct AnswerverifiedShow Answer

After drawing the Lewis dot structure for XeCl2, determine the number of single bonds, double bonds, and lone pairs on the central atom.

Correct AnswerverifiedShow Answer

A chemical bond for which one of the bonded atoms provides both electrons for the bond is referred to as a:

Correct AnswerverifiedB

Given the following bond lengths in pm: C-C, 154; C = C, 134; Cl - Cl, 199 What is the best estimate of the C-Cl bond length in CCl4 in pm?

Correct AnswerverifiedShow Answer

Given the listed average bond energies, calculate the enthalpy change for the production of 48 g of methanol by the reaction: CO2(g) + 3 H2(g) → CH3OH(g) + H2O(g) C-O/360 kJ/mol C=O/736 kJ/mol H-H/436 kJ/mol H-O/464 kJ/mol H-C/414 kJ/mol

Correct AnswerverifiedShow Answer

Which of the following species exhibits resonance?

Correct AnswerverifiedShow Answer

With the representations of "I" for ionic bond, "PC" for polar covalent bond, and "NP" for nonpolar covalent bond, which of the following descriptive combinations is correct?

Correct AnswerverifiedShow Answer

What is the correct molecular geometry for the carbon atom in urea (NH2) 2CO?

Correct AnswerverifiedShow Answer

Choose the INCORRECT statement.

Correct AnswerverifiedShow Answer

Given the bond enthalpies N≡N (946) , H-H (436) , H-N (389) , all in kJ/mol, estimate ΔH for the following reaction: N2(g) + 3 H2(g) → 2NH3(g) .

Correct AnswerverifiedShow Answer

Which of the following species has a pyramidal structure?

Correct AnswerverifiedShow Answer

Which chloride should have the greatest covalent character?

Correct AnswerverifiedShow Answer

Choose the INCORRECT statement.

Correct AnswerverifiedShow Answer

Which of the following species is best represented by a resonance hybrid having two contributing structures?

Correct AnswerverifiedShow Answer

Given the bond enthalpies N-H (389) , Cl-Cl (243) , N-Cl (201) , and H-Cl (431) in kJ/mol, compute ΔH° in kJ/mol for NH₃(g) + Cl₂(g) → NH₂Cl + HCl(g)

Correct Answer
verified
E

What is the bond order for the carbon-oxygen bond in formaldehyde (CH₂O) , which has no O-H bonds?

Correct Answer
verified

Correct Answer
verified
E

Correct Answer
verified

After drawing the Lewis dot structure for BeCl₂, determine the number of single bonds, double bonds, and lone pairs on the central atom.

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

After drawing the Lewis dot structure for XeCl₂, determine the number of single bonds, double bonds, and lone pairs on the central atom.

Correct Answer
verified

Correct Answer
verified
B

Given the following bond lengths in pm: C-C, 154; C = C, 134; Cl - Cl, 199 What is the best estimate of the C-Cl bond length in CCl₄ in pm?

Correct Answer
verified

Given the listed average bond energies, calculate the enthalpy change for the production of 48 g of methanol by the reaction: CO₂(g) + 3 H₂(g) → CH₃OH(g) + H₂O(g) C-O/360 kJ/mol C=O/736 kJ/mol H-H/436 kJ/mol H-O/464 kJ/mol H-C/414 kJ/mol

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

What is the correct molecular geometry for the carbon atom in urea (NH₂) ₂CO?

Correct Answer
verified

Correct Answer
verified

Given the bond enthalpies N≡N (946) , H-H (436) , H-N (389) , all in kJ/mol, estimate ΔH for the following reaction: N₂(g) + 3 H₂(g) → 2NH₃(g) .

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified