Question 1

If four orbitals on one atom overlap four orbitals on a second atom,how many molecular orbitals will form?
A)1
B)4
C)8
D)16
E)none of these

Accepted Answer

Each orbital on the first atom can overlap with one of the four orbitals on the second atom, resulting in four molecular orbitals. Since there are four orbitals on each atom, there will be a total of 8 molecular orbitals formed.

Question 2

If a molecule demonstrates paramagnetism,then :
I.The substance can have both paired and unpaired electrons.
II.The bond order is not a whole number.
III.It can be determined by drawing a Lewis structure.
IV.It must be an ion.
A)I,II
B)I,II,IV
C)II,III
D)I only
E)All of the above are correct.

Accepted Answer

Paramagnetism is primarily determined by the presence of unpaired electrons in a molecule, not necessarily by the bond order, the ability to draw a Lewis structure, or the molecule being an ion. While a paramagnetic substance can have both paired and unpaired electrons, the other statements are not universally true for all paramagnetic substances.

Question 3

Which of the following species is paramagnetic? A)C₂ B)O₂ C)F₂ D)Li₂ E)none of these

Accepted Answer

Oxygen (O) has two unpaired electrons in its molecular orbital configuration, making it paramagnetic.

Question 4

Which of the following species has the largest dissociation energy? A)O₂ B)O₂^- C)O₂²^- D)O₂⁺ E)O₂²⁺

Accepted Answer

The dissociation energy of a molecule is the energy required to break the bond between two atoms. The more stable the bond, the higher the dissociation energy. The stability of a bond depends on the number of electrons in the bond and the electronegativity of the atoms involved. In general, bonds with more electrons are more stable than bonds with fewer electrons, and bonds between atoms with large electronegativity differences are more stable than bonds between atoms with small electronegativity differences.In the case of the oxygen molecule, O2, the bond is formed by two oxygen atoms sharing two electrons. The electronegativity of oxygen is 3.44, which is relatively high. This means that the oxygen atoms have a strong attraction for the electrons in the bond, which makes the bond stable. The dissociation energy of O2 is 498 kJ/mol.The other species listed in the question are all ions of oxygen. Ions are atoms or molecules that have lost or gained electrons, which gives them a net charge. The dissociation energy of an ion is the energy required to remove an electron from the ion. In general, the more positive the charge of an ion, the higher the dissociation energy. This is because the more positive the charge, the more strongly the ion attracts electrons.In the case of the oxygen ions, the dissociation energy increases as the charge of the ion increases. This is because the more positive the charge, the more strongly the ion attracts electrons. The dissociation energy of O2+ is 1175 kJ/mol, the dissociation energy of O22+ is 1902 kJ/mol, and the dissociation energy of O2- is 849 kJ/mol.Therefore, the species with the largest dissociation energy is O22+.

Question 5

Which of the following diatomic molecules has a bond order of 2? A)B₂ B)C₂ C)P₂ D)F₂ E)Li₂

Accepted Answer

The answer of Which of the following diatomic molecules has...

Question 6

For how many of the following does the bond order decrease if you add one electron to the neutral molecule? B₂,C₂,P₂,F₂ A)0 B)1 C)2 D)3 E)4

Accepted Answer

The bond order is defined as 1/2 times the difference between the number of bonding and anti-bonding electrons in a molecule. When you add an electron to a neutral molecule, it goes into an anti-bonding orbital and hence increases the number of anti-bonding electrons, thus decreasing the bond order. This effect is observed in CS and PS molecules, where the bond orders decrease by 0.5 upon addition of an electron. However, in the cases of BS and F molecules, the additional electron enters a non-bonding orbital and does not affect the bonding-anti-bonding balance, hence the bond order remains the same. Therefore, the correct answer is C) 2.

Question 7

Order the following from shortest to longest bond: C₂,B₂,H₂,N₂ A)H₂,N₂,C₂,B₂ B)N₂,C₂,B₂,H₂ C)C₂,N₂,H₂,B₂ D)C₂,B₂,H₂,N₂ E)none of these

Accepted Answer

The bond length is inversely related to bond order. N₂ has a triple bond, making it the shortest. H₂ has a single bond but is very short due to the small size of hydrogen atoms. C₂ has a double bond, and B₂ has a single bond, making it the longest.

Question 8

Which of the following has the largest bond order? A)N₂ B)N₂^- C)N₂²^- D)N₂⁺ E)N₂²⁺

Accepted Answer

N2 has the largest bond order because it has the least number of electrons in the antibonding orbitals.

Question 9

As the bond order of a bond increases,the bond energy ______ and the bond length ______.
A)increases,increases
B)decreases,decreases
C)increases,decreases
D)decreases,increases
E)More information is needed to answer this question.

Accepted Answer

Bond order is directly proportional to bond energy and inversely proportional to bond length. As the bond order increases, with more electron density between two atoms, bond energy increases. At the same time, the bond length decreases because of the increased attraction between the nuclei and the shared electrons. Therefore, the correct answer is C).

Question 10

Larger bond order means greater bond strength.

Accepted Answer

Bond order is a measure of the number of bonds between two atoms in a molecule or ion. A bond with a larger bond order has more bonds, indicating a stronger bond and shorter bond length. Therefore, larger bond order means greater bond strength.

Question 11

When an electron pair is shared in the area centered on a line joining the atoms,a  $\sigma$ (sigma)bond is formed.

Accepted Answer

This is true. A sigma bond is formed when electron pairs are shared in the area centered on a line joining the atoms.

Question 12

The electron configuration of a particular diatomic species is ( $\sigma$_2s)²( $\sigma$*_2s)²( $\sigma$_2p)²($\pi$_2p)⁴($\pi$*_2p)².What is the bond order for this species? A)3.5 B)3 C)2.5 D)2 E)1.5

Accepted Answer

The bond order is calculated as (number of bonding electrons - number of antibonding electrons) / 2. Here, there are 8 bonding electrons and 4 antibonding electrons, so the bond order is (8-4)/2 = 2.

Question 13

The hybridization of a molecule is measured to determine the shape of the molecule.

Accepted Answer

Hybridization is a concept used to describe the electronic structure of atoms within a molecule, which can influence the molecule's shape, but it is not a measurement. The shape of a molecule is typically determined by the VSEPR (Valence Shell Electron Pair Repulsion) theory.

Question 14

The configuration ( $\sigma$_2s)²( $\sigma$_2s*)²($\pi$_2py)¹($\pi$_2px)¹ is the molecular orbital description for the ground state of A)Li₂⁺ B)Be₂ C)B₂ D)B₂²^- E)C₂

Accepted Answer

The configuration given describes the ground state of Boron (B) which has the electron configuration 1s2 2s2 2p1. The notation used in the configuration given represents the molecular orbitals formed by combining the atomic orbitals of the different atoms involved in the molecule. In this case, there is only one atom (Boron) so the molecular orbital description represents the electron configuration of the atom in its ground state. Therefore, the correct answer is C which corresponds to Boron (B).

Question 15

Which charge(s)on an O₂ ion would give a bond order of 2.5? A)-2 B)-1 C)+1 D)two of these E)none of these

Accepted Answer

Bond order is determined by the difference between the number of bonding electrons and the number of antibonding electrons, divided by two. A charge of +1 on the ion will increase the number of bonding electrons, leading to a higher bond order. The other options (-2 and -1) will decrease the number of bonding electrons, leading to a lower bond order. Therefore, the best choice for a bond order of 2.5 is C (+1 charge).

Question 16

What is the bond order of He₂⁺? A)0 B) C)1 D) E)2

Accepted Answer

The answer of What is the bond order of He₂⁺? A)0 B)...

Question 17

The fact that O₂ is paramagnetic can be explained by A)the Lewis structure of O₂ B)resonance C)a violation of the octet rule D)the molecular orbital diagram for O₂ E)hybridization of atomic orbitals in O₂

Accepted Answer

Paramagnetism is observed in molecules with unpaired electrons, and the molecular orbital diagram provides information about the electron distribution in a molecule. Therefore, the best choice is D, which considers the molecular orbital diagram for O₂.

Question 18

For which of the following diatomic molecules would the bond order become greater if an electron is removed (i.e. ,if the molecule is converted to the positive ion in its ground state)? A)B₂ B)C₂ C)P₂ D)F₂ E)Na₂

Accepted Answer

The bond order of a diatomic molecule is defined as half the difference between the number of bonding electrons and the number of antibonding electrons. Removing an electron in the case of F2 would result in the creation of a F+ ion, which has one less electron than F2, and therefore one less antibonding electron. As a result, the bond order would increase, making D the correct answer.

Question 19

When comparing Be₂ and H₂: I.Be₂ is more stable because it contains both bonding and antibonding valence electrons. II.H₂ has a higher bond order than Be₂. III.H₂ is more stable because it only contains $\sigma$_1s electrons. IV.H₂ is more stable because it is diamagnetic,whereas Be₂ is paramagnetic. A)I,II B)III only C)II,III D)II,III,IV E)III,IV

Accepted Answer

H₂ has a higher bond order than Be₂, making it more stable. H₂ is more stable because it only contains bonding electrons.

Question 20

How many of the following: F₂,B₂,O₂,N₂ ,are paramagnetic? A)0 B)1 C)2 D)3 E)4

Accepted Answer

F2 and N2 are diamagnetic, while B2 and O2 are paramagnetic due to unpaired electrons in their molecular orbitals.

Quiz 9: Covalent Bonding: Orbitals

If four orbitals on one atom overlap four orbitals on a second atom,how many molecular orbitals will form?

If a molecule demonstrates paramagnetism,then : I.The substance can have both paired and unpaired electrons. II.The bond order is not a whole number. III.It can be determined by drawing a Lewis structure. IV.It must be an ion.

Which of the following species is paramagnetic?

Which of the following species has the largest dissociation energy?

Which of the following diatomic molecules has a bond order of 2?

For how many of the following does the bond order decrease if you add one electron to the neutral molecule? B₂,C₂,P₂,F₂

Order the following from shortest to longest bond: C₂,B₂,H₂,N₂

Which of the following has the largest bond order?

As the bond order of a bond increases,the bond energy and the bond length .

Larger bond order means greater bond strength.

When an electron pair is shared in the area centered on a line joining the atoms,a $\sigma$ (sigma)bond is formed.

The electron configuration of a particular diatomic species is ( $\sigma$ _2s) ²( $\sigma$ _2s) ²( $\sigma$ _2p) ²( $\pi$ _2p) ⁴( $\pi$ _2p) ².What is the bond order for this species?

The hybridization of a molecule is measured to determine the shape of the molecule.

The configuration ( $\sigma$ _2s) ²( $\sigma$ _2s*) ²( $\pi$ _2py) ¹( $\pi$ _2px) ¹ is the molecular orbital description for the ground state of

Which charge(s) on an O₂ ion would give a bond order of 2.5?

What is the bond order of He₂⁺?

The fact that O₂ is paramagnetic can be explained by

For which of the following diatomic molecules would the bond order become greater if an electron is removed (i.e. ,if the molecule is converted to the positive ion in its ground state) ?

How many of the following: F₂,B₂,O₂,N₂ ,are paramagnetic?

Quiz 9: Covalent Bonding: Orbitals

If four orbitals on one atom overlap four orbitals on a second atom,how many molecular orbitals will form?

If a molecule demonstrates paramagnetism,then : I.The substance can have both paired and unpaired electrons. II.The bond order is not a whole number. III.It can be determined by drawing a Lewis structure. IV.It must be an ion.

Which of the following species is paramagnetic?

Which of the following species has the largest dissociation energy?

Which of the following diatomic molecules has a bond order of 2?

For how many of the following does the bond order decrease if you add one electron to the neutral molecule? B2,C2,P2,F2

Order the following from shortest to longest bond: C2,B2,H2,N2

Which of the following has the largest bond order?

As the bond order of a bond increases,the bond energy ______ and the bond length ______.

Larger bond order means greater bond strength.

When an electron pair is shared in the area centered on a line joining the atoms,a σ\sigmaσ (sigma)bond is formed.

The electron configuration of a particular diatomic species is ( σ\sigmaσ 2s) 2( σ\sigmaσ *2s) 2( σ\sigmaσ 2p) 2( π\piπ 2p) 4( π\piπ *2p) 2.What is the bond order for this species?

The hybridization of a molecule is measured to determine the shape of the molecule.

The configuration ( σ\sigmaσ 2s) 2( σ\sigmaσ 2s*) 2( π\piπ 2py) 1( π\piπ 2px) 1 is the molecular orbital description for the ground state of

Which charge(s) on an O2 ion would give a bond order of 2.5?

What is the bond order of He2+?

The fact that O2 is paramagnetic can be explained by

For which of the following diatomic molecules would the bond order become greater if an electron is removed (i.e. ,if the molecule is converted to the positive ion in its ground state) ?

How many of the following: F2,B2,O2,N2 ,are paramagnetic?

For how many of the following does the bond order decrease if you add one electron to the neutral molecule? B₂,C₂,P₂,F₂

Order the following from shortest to longest bond: C₂,B₂,H₂,N₂

As the bond order of a bond increases,the bond energy and the bond length .

When an electron pair is shared in the area centered on a line joining the atoms,a $\sigma$ (sigma)bond is formed.

The electron configuration of a particular diatomic species is ( $\sigma$ _2s) ²( $\sigma$ _2s) ²( $\sigma$ _2p) ²( $\pi$ _2p) ⁴( $\pi$ _2p) ².What is the bond order for this species?

The configuration ( $\sigma$ _2s) ²( $\sigma$ _2s*) ²( $\pi$ _2py) ¹( $\pi$ _2px) ¹ is the molecular orbital description for the ground state of

Which charge(s) on an O₂ ion would give a bond order of 2.5?

What is the bond order of He₂⁺?

The fact that O₂ is paramagnetic can be explained by

How many of the following: F₂,B₂,O₂,N₂ ,are paramagnetic?