Deck 9: The Basics of Chemical Bonding

Question 1

Which of the following statements is true?

A)Bond formation tends to increase the potential energy of the atoms involved.
B)Compounds with negative heats of formation tend to be unstable with respect to decomposition into their elements.
C)When $\Delta$ H°_f is negative, the reaction produces a stable compound.
D)An endothermic reaction produces a fairly stable compound.
E)Compounds with positive heats of formation tend to be stable with respect to decomposition into their elements.

Answer 1

When $\Delta$ H°_f is negative, the reaction produces a stable compound.

Question 2

Based on the $\Delta$ H°_f data given, which compound is the most stable?

A)N₂O₄(g), +9.7 kJ/mol
B)H₂S(g), -20.6 kJ/mol
C)N₂H₄(g), +94.5 kJ/mol
D)PH₃(g), +5.4 kJ/mol
E)NH₃(g), -46.4 kJ/mol

Answer 2

NH₃(g), -46.4 kJ/mol

Question 3

Based on the $\Delta$ H°_f data given, which of the following compounds is the most unstable?

A)SrO(s), -592.0 kJ/mol
B)CsBr(s), -396 kJ/mol
C)CaF₂(s), -1215 kJ/mol
D)NaI(s), -288 kJ/mol
E)KF(s), -568.6 kJ/mol

Answer 3

CaF₂(s), -1215 kJ/mol

Question 4

Based on the $\Delta$ H°_f data given, which compound is the most stable?

A)CO₂(g), -393.5 kJ/mol
B)NO₂(g), +33.85 kJ/mol
C)NO(g), +90.4 kJ/mol
D)CO(g), -110.5 kJ/mol
E)NH₃(g), -46.4 kJ/mol

Question 5

Given that the first ionization energy of cesium is +376 kJ/mol and the electron affinity of bromine is -325 kJ/mol, calculate $\Delta$ E for the reaction, Cs(g)+ Br(g)s Cs⁺(g)+ Br^?(g).

A)+376 kJ/mol
B)+701 kJ/mol
C)+51 kJ/mol
D)-701 kJ/mol
E)-51 kJ/mol

Question 6

Lithium fluoride has a lattice energy of -1033 kJ/mol. In the ionic solid AB, A²⁺ has approximately the same radius as Li⁺, and B^2- has approximately the same radius as F^?. What is a reasonable estimate of the lattice energy of AB?

A)About 3 × (-1033 kJ/mol)
B)About -1033 kJ/mol
C)About 4 × (-1033 kJ/mol)
D)About 2 × (-1033 kJ/mol)
E)About 6 × (-1033 kJ/mol)

Question 7

Which ionic solid is likely to have the largest exothermic lattice energy?

A)KCl
B)NaCl
C)LiCl
D)CsCl
E)They all have the same value.

Question 8

Which of the following solids is likely to have the largest exothermic lattice energy?

A)LiF
B)NaCl
C)AlCl₃
D)Al₂O₃
E)CaCl₂

Question 9

Which ionic solid is likely to have the least exothermic lattice energy?

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

Question 10

Which of the following solids is likely to have the least exothermic lattice energy?

A)LiF
B)NaCl
C)AlCl₃
D)Al₂O₃
E)CaCl₂

Question 11

Which of the following solids would have the highest melting point?

A)LiF
B)NaCl
C)AlCl₃
D)Al₂O₃
E)CaCl₂

Question 12

Which of the following statements is true in relation to the formation of the stable ionic compound sodium chloride?Hint: Consider why the sodium to chloride bond occurs.

A)The net absorption of 147 kJ/mol of energy for the formation of the gaseous sodium and chloride ions is mainly responsible for the formation of the stable ionic compound.
B)The lattice energy provides the necessary stabilization energy for the formation of sodium chloride.
C)Sodium chloride is stable because it is formed from the combination of isolated gaseous ions.
D)The first ionization energy of sodium contributes favorably to the overall formation of sodium chloride.
E)The release of energy as the solid sodium chloride is formed leads to an overall increase in the potential energy.

Question 13

For two ions with charges q₁ and q₂ separated by distance r, the potential energy canbe calculated from Coulomb's law: E = Calculate the energy released when 1 mole NaCl is formed if the constant k = 1.11 × 10^-10 C²/J·m, the charge Na⁺ = +1 e, and the charge on Cl^- is -1 e, e = 1.602 × 10^-19 C, and

A)+308 kJ/mol
B)+8.20 kJ/mol
C)-297 kJ/mol
D)-494 kJ/mol
E)-371 kJ/mol

Question 14

Sodium forms a monatomic ion that has the electron configuration of a noble gas. What is the electron configuration of that noble gas?

A)1s²
B)1s² 2p⁶
C)1s² 2s² 2p⁶
D)1s² 2s² 2p⁶ 3s²
E)1s² 2s² 2p⁶ 3s² 3p⁶

Question 15

Magnesium forms a monatomic ion that has the electron configuration of a noble gas. What is the electron configuration of that noble gas?

A)1s² 2p⁶
B)1s² 2s² 2p⁶
C)1s² 2s² 2p⁶ 3s¹
D)1s² 2s² 2p⁶ 3s²
E)1s² 2s² 2p⁶ 3s² 3p⁶

Question 16

Bromine tends to form a monatomic ion that has the electron configuration of a noble gas. What is the symbol of that noble gas?

A)Ne
B)Ar
C)Kr
D)Xe
E)Rn

Question 17

Sulfur tends to form a monatomic ion that has the electron configuration of a noble gas. What is the symbol of the noble gas?

A)Ne
B)Ar
C)Kr
D)Xe
E)Rn

Question 18

The octet rule is generally followed for cations of elements located where on the periodic table?

A)post transition metals and transition metals
B)Group IA and Group IIA metals
C)Group IVA elements
D)lanthanide elements
E)actinide elements

Question 19

Which ion of uranium has a noble gas electron configuration?

A)U²⁺
B)U³⁺
C)U⁴⁺
D)U⁶⁺
E)U^2-

Question 20

Which ion has a noble gas electron configuration?

A)Fe³⁺
B)Sn²⁺
C)Ni²⁺
D)Ti⁴⁺
E)Cr³⁺

Question 21

Which ion has a noble gas electron configuration?

A)Fe³⁺
B)Ni²⁺
C)Sc³⁺
D)V³⁺
E)Cr³⁺

Question 22

Which atom has the same electron configuration as In³⁺?

A)Te
B)Pd
C)Ir
D)Zn
E)Ga

Question 23

Give the ground state electron configuration and number of unpaired electrons for Sb³⁺. Hint: Draw the orbital diagram of Sb^{3+ to determine unpaired electrons.}

A)[Kr] 4d¹ 5s¹; 2 unpaired electrons
B)[Ar]; 1 unpaired electron
C)[Kr] 4d¹⁰ 5s²; 0 unpaired electrons
D)[Kr] 4d⁷ 5s²; 3 unpaired electrons
E)[Ar] 4d⁴ 5s²; 4 unpaired electrons

Question 24

Give the ground state electron configuration and number of unpaired electrons for V³⁺. Hint: Draw the orbital diagram of V^{3+ to determine unpaired electrons.}

A)[Ar] 3d¹; 2 unpaired electrons
B)[Ar]; 1 unpaired electron
C)[Ar] 3d²; 2 unpaired electrons
D)[Ar] 3d³; 3 unpaired electrons
E)[Ar] 3d⁴; 4 unpaired electrons

Question 25

Which metal ion is expected to have the electron configuration [Kr]4d⁴? Hint: Remember that positive ions lose electrons.

A)Mn²⁺
B)Ru²⁺
C)Zr²⁺
D)Mo²⁺
E)Sr²⁺

Question 26

Which element below has three valence electrons in its Lewis symbol?

A)gallium
B)fluorine
C)iron
D)nickel
E)sulfur

Question 27

Which species below has eight valence electrons in its Lewis symbol?

A)Ar⁺
B)F⁺
C)Mg⁺
D)S^2-
E)Si

Question 28

Which species below has the lowest number of valence electrons in its Lewis symbol?

A)Ar⁺
B)Ga⁺
C)Mg²⁺
D)S^2-
E)F^?

Question 29

Which element below includes six electrons in its Lewis symbol?

A)Cr
B)Ni
C)Ba
D)Se
E)As

Question 30

Which species has the most valence electrons in its Lewis symbol?

A)Ar⁺
B)Ga⁺
C)Ba²⁺
D)Br
E)O^2?

Question 31

The atoms in the nitrogen molecule, N₂, are held together by Hint: Draw the Lewis structure of the molecule.

A)a single covalent bond.
B)a double covalent bond.
C)a triple covalent bond.
D)an ionic bond.
E)a magnetic dipole bond.

Question 32

The atoms in the oxygen molecule, O₂, are held together by Hint: Draw the Lewis structure of the molecule.

A)a single covalent bond.
B)a double covalent bond.
C)a triple covalent bond.
D)an ionic bond.
E)a magnetic dipole bond.

Question 33

A covalent bond is characterized by two properties. These are

A)the energy of the bond and the location of the electron pair in the bond.
B)the energy of the separated atoms and the energy of the new bond.
C)the bond length and the polarity of the covalent bond.
D)the bond length and the bond energy.
E)the energy released when a bond forms, and the electronegativities of the two atoms.

Question 34

The Lewis symbol for the carbon atom has ________ valence electrons. The number of covalent bonds that carbon usually forms to complete its valence shell and obey the octet rule is ________.

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

Question 35

The Lewis symbol for the nitrogen atom has ________ valence electrons. The number of covalent bonds that nitrogen usually forms to complete its valence shell and obey the octet rule is ________.

A)5, 1
B)5, 2
C)3, 4
D)5, 3
E)5, 4

Question 36

Which statement below is true?Hint: Consider how properties of a covalent bond are measured.

A)The two electrons in a single covalent bond must be paired as required by the Pauli exclusion principle.
B)One mole of hydrogen atoms is more stable than one mole of hydrogen molecules.
C)The buildup of electron density between two atoms repels each nucleus, making them less stable.
D)The bond energy is the minimum energy required to bring about pairing of the electrons in a covalent bond.
E)As the distance between the nuclei decreases when forming a covalent bond, there is a corresponding decrease in the probability of finding both electrons near either nucleus.

Question 37

Which bond is the most polar?

A)H-C
B)H-Cl
C)H-P
D)H-S
E)H-Se

Question 38

Which bond is the most polar?

A)H-C
B)H-S
C)H-P
D)H-O
E)H-Se

Question 39

Which bond is the most polar?Hint: Consider the electronegativity values of each element.

A)Al-I
B)Si-I
C)Al-Cl
D)Si-Cl
E)Si-P

Question 40

Which bond is the most polar?Hint: Consider the electronegativity values of each element.

A)Br-Br
B)S-O
C)C-P
D)C-O
E)B-O

Question 41

Which bond is the most polar?Hint: Consider the electronegativity values of each element.

A)B-C
B)C-N
C)C-O
D)Si-O
E)C-C

Question 42

Arrange the following in terms of increasing electronegativity values.Ga, P, As, Ge

A)Ga < Ge < As < P
B)Ge < Ga < As < P
C)P < Ge < Ga < As
D)P < As < Ge < Ga
E)As < Ge < As

Question 43

Based on electronegativity considerations, which species is predicted to be the strongest oxidizing agent?

A)Ne
B)Kr
C)Br₂
D)Cl₂
E)S

Question 44

Arrange the following in terms of decreasing electronegativity values.P, O, As, S Hint: Remember to refer to your periodic table for trends.

A)P > O > As > S
B)As > P > S > O
C)S > O > P > As
D)As > S > P > O
E)O > S > P > As

Question 45

In the chlorine monoxide molecule, chlorine has a charge of +0.167 e^-. If the bond length is 154.6 pm, calculate the dipole moment of the molecule in debyes. Hint: Watch your units carefully with this problem.

A)3.11 D
B)2.30 D
C)0.167 D
D)1.24 D
E)1.65 D

Question 46

In the nitrogen monoxide molecule, the dipole moment is 0.16 D and the bond length is 115 pm. Determine the sign and magnitude of the charge on the oxygen atom. Hint: Watch your units carefully with this problem.

A)-1.3 e^-
B)-0.029 e^-
C)-0.097 e^-
D)-0.72 e^-
E)+1.3 e^-

Question 47

Based on the "best"Lewis structure after applying formal charge considerations, how many non-bonding valence electrons are around the nitrogen atom in the nitrate ion?

A)0
B)2
C)4
D)6
E)8

Question 48

Draw the Lewis structure for HClO₂ from the skeletal structure presented below. If the valence shells are filled to the usual limit (a maximum of 8), how many nonbonding valence electrons are in the molecule?

A)14
B)16
C)18
D)20
E)26

Question 49

Draw the Lewis structure for HNO_2. If the valence shells are filled to the usual limit (a maximum of 8), how many nonbonding valence electrons are in the molecule?

A)0
B)2
C)6
D)10
E)14

Question 50

Draw a Lewis structure for CH₂Cl₂. Based on this Lewis structure, the calculated value for the formal charge on the carbon atom is

A)0.
B)4+.
C)2+.
D)2-.
E)4-.

Question 51

Draw a Lewis structure for NH₄⁺. Based on this Lewis structure, the calculated value for the formal charge on the nitrogen atom is

A)0.
B)4+.
C)1+.
D)1-.
E)4- .

Question 52

When the fluoride ion reacts with a BF₃ molecule (a molecule in which there are no multiple bonds), an ion is formed in which the boron atom is the central atom. The bond between the boron trifluoride and the fluoride ion is

A)an ionic bond.
B)a regular covalent bond, where both species contribute 1 electron to the bond.
C)a coordinate covalent bond.
D)a resonance hybrid bond.
E)a bond where two atoms share one electron instead of two.

Question 53

How many coordinate covalent bonds are formed in the reaction between H⁺ and NH₃ and what is the formula of the only product?

A)0, NH₃
B)1, NH₄⁺
C)2, NH₄⁺
D)3, N₂H₄⁺
E)4, N₂H₅⁺

Question 54

How many coordinate covalent bonds are formed in this product in the reaction between F^- and BF₃ and what is the formula of the product?

A)BF₃, 0
B)BF₄^-, 1
C)BF₄^-, 2
D)BF₅^2-, 3
E)B₂F₅^-, 4

Question 55

When the hydrogen ion combines with a water molecule, a coordinate covalent bond is formed because

A)a monatomic species reacts with a molecular substance.
B)both electrons are supplied by the oxygen atom of the water molecule.
C)a nonpolar bond is formed.
D)a polyatomic species is formed.
E)a bond is formed where two atoms share one electron instead of two.

Question 56

Draw the Lewis structure for hydrogen peroxide, H₂O₂. Based on this structure, how many polar bonds and non-polar bonds are present?

A)3 polar bonds and no non-polar bonds
B)2 polar bonds and 1 non-polar bond
C)1 polar bond and 2 non-polar bonds
D)no polar bonds and 3 non-polar bonds
E)2 polar bonds and 2 non-polar bonds

Question 57

How many lone pairs of electrons are in the nitric oxide molecule?

A)2
B)1
C)0
D)3
E)4

Question 58

The formal charge on the nitrogen atom in the nitrate ion (NO₃^-)is

A)3-
B)0
C)1+
D)3+
E)5+

Question 59

The formal charge on the carbon atom in the carbonate (CO₃^2-)ion is

A)2-.
B)0.
C)1+.
D)2+.
E)4+.

Question 60

Based on the "best"Lewis structure after applying formal charge considerations, how many non-bonding valence electrons are around the carbon atom in the CO molecule?

A)0
B)2
C)4
D)6
E)8

Question 61

Based on the "best"Lewis structure after applying formal charge considerations, how many non-bonding valence electrons are around the nitrogen atom in the nitrite ion (NO₂^-)?

A)0
B)2
C)4
D)6
E)8

Question 62

Based on the "best"Lewis structure after applying formal charge considerations, how many non-bonding valence electrons are around the nitrogen atom in the HCN molecule?

A)0
B)1
C)2
D)4
E)6

Question 63

Draw the Lewis structure for HClO₃. If the valence shells are filled to the usual limit (a maximum of 8), what is the formal charge on the chlorine atom? Hint: Do not forget about double or triple bonds potentially being in the Lewis structure.

A)-1
B)0
C)+1
D)+2
E)+3

Question 64

Draw the Lewis structure for H₂SeO₃. If the valence shells are filled to the usual limit (a maximum of 8), how many nonbonding valence electrons are there in the molecule? Hint: Do not forget about double or triple bonds potentially being in the Lewis structure.

A)14
B)16
C)18
D)20
E)28

Question 65

Draw a Lewis structure for H₃C-NH₂. Based on this Lewis structure, the calculated value for the formal charge on the nitrogen atom is Hint: Do not forget about double or triple bonds potentially being in the Lewis structure.

A)2-.
B)3+.
C)3-.
D)2+.
E)0.

Question 66

Draw the Lewis structure for the H₂CO molecule. Based on this structure, how many polar bonds and non-polar bonds are present? Hint: Do not forget about double or triple bonds potentially being in the Lewis structure.

A)3 polar bonds and no non-polar bonds
B)2 polar bonds and 1 non-polar bond
C)1 polar bond and 2 non-polar bonds
D)no polar bonds and 3 non-polar bonds
E)2 polar bonds and 2 non-polar bonds

Question 67

Draw the Lewis structure for the F₂CO molecule. Based on this structure, how many polar bonds and non-polar bonds are present? Hint: Do not forget about double or triple bonds potentially being in the Lewis structure.

A)3 polar bonds and no non-polar bonds
B)2 polar bonds and 1 non-polar bond
C)1 polar bond and 2 non-polar bonds
D)no polar bonds and 3 non-polar bonds
E)2 polar bonds and 2 non-polar bonds

Question 68

Which species has the same bond order as the carbon monoxide molecule?

A)ClF
B)CO₃^2-
C)CO₂
D)NO⁺
E)O₃

Question 69

The metaphosphate ion, PO₃^-, is the structural analog of the NO₃^- ion with respect to the arrangement of the atoms in the ion. After drawing the "best"Lewis structure for the metaphosphate ion based on formal charge considerations, what is the formal charge on the phosphorus atom? Hint: Do not forget about double or triple bonds potentially being in the Lewis structure.

A)1-
B)0
C)1+
D)2+
E)5+

Question 70

Draw the Lewis structure for H₂SeO₄. If the valence shells are filled to the usual limit (a maximum of 8), what is the formal charge on the Se? Hint: Do not forget about double or triple bonds potentially being in the Lewis structure.

A)2-
B)1-
C)0
D)1+
E)2+

Question 71

Draw the Lewis structure for H₂SO₄. Experimentally, it is known that the S-O bonds are shorter than the S-OH bonds. The likely explanation for this is Hint: Consider the number of bonded electrons in each bond.

A)the electrons in the S-OH bonds are not equally shared.
B)the sulfur atom is not as electronegative as the oxygen atom.
C)the hydrogen atom is weakly bonded to the other S atom.
D)there are no lone pairs on the hydrogen atom.
E)the S-O bond has a greater bond order than the S-OH bond.

Question 72

Draw the Lewis structure for HClO₃. If the valence shells are filled to the usual limit (a maximum of 8), what is the sum of the absolute values of all the formal charges in the molecule? Hint: Minimize formal charge to ensure you have the most stable or "best"Lewis structure.

A)0
B)1
C)2
D)3
E)4

Question 73

Draw a Lewis structure for CH₃NO₂. Based on the Lewis structure, what is the formal charge on the nitrogen atom for the most favorable structure? Hint: Minimize formal charge to ensure you have the most stable or "best"Lewis structure.

A)-2
B)-1
C)0
D)+1
E)+2

Question 74

Draw the "best"Lewis structure for sulfur trioxide based on formal charge considerations. The number of resonance structures is

A)1 (no resonance structures).
B)2.
C)3.
D)4.
E)5.

Question 75

Based on the "best"Lewis structure from formal charge considerations, how many resonance structures, if any, can be drawn for the PO₄^3- ion?

A)1 (no resonance structures)
B)2
C)3
D)4
E)5

Question 76

The metaphosphate ion, PO₃^-, is the structural analog of the NO₃^- ion with respect to the arrangement of the atoms in the ion. After drawing the "best"Lewis structure for the metaphosphate ion based on formal charge considerations, what is the number of resonance structures for this "best"Lewis structure? Hint: Use formal charge to help determine how many realistic resonance structures there are for the metaphosphate ion.

A)1 (no resonance structures)
B)2
C)3
D)4
E)5

Question 77

How many resonance structures, if any, can be drawn for the N₂O₅ molecule? Hint: Consider formal charge when determining if the resonance structure is valid.

A)1 (no resonance structures)
B)2
C)3
D)4
E)5

Question 78

The chlorite ion has a Lewis structure that is based on the skeletal structure shown below: O=Cl -O
Draw the Lewis structure minimizing the formal charges present in the structure. Based on this structure, the chlorite ion has ,Hint: Consider all possible resonance structures when working with formal charge.

A)two single bonds, the sum of absolute values of formal charges = 3, and no resonance hybrids.
B)one single and one double bond, sum of absolute values of formal charges = 5, and two contributing resonance hybrids.
C)one single and one double bond, sum of absolute values of formal charges = 3, and two contributing resonance hybrids.
D)two double bonds, sum of absolute values of formal charges = 1, and no resonance hybrids.
E)one single and one double bond, sum of absolute values of formal charges = 1, and two contributing resonance hybrids.

Question 79

The carbonate ion has the skeletal structure as shown below. Complete the Lewis structure by filling in the bonds and the remaining valence electrons which are not involved in bonds. Which statement made about the carbonate ion is true? Based on its Lewis structure, the carbonate ion should have ________ resonance hybrids and ________ atoms with formal charges on them in its structure. Hint: Consider the possible places the double bond could go when determining resonance of carbonate.

A)2, 2
B)3, 1
C)3, 2
D)2, 1
E)no, 2

Question 80

Draw the Lewis structure of CH₃NO_2.Based on its structure, the nitromethane molecule should have ________ resonance hybrids and ________ atoms with formal charges on them. Hint: Consider possible double and triple bonds in the structure and be sure to minimize formal charge.

A)no, 2
B)no, 3
C)2, 2
D)2, 3
E)3, 2