Q: What is the formula for calculating bond order in Molecular Orbital Theory?

$$\text{Bond Order} = \frac{\text{Number of electrons in bonding MOs} - \text{Number of electrons in antibonding MOs}}{2}$$

Question 1

Which statement best describes the main difference between Valence Bond Theory and Molecular Orbital Theory?

Accepted Answer

Valence Bond Theory explains bonding by overlapping half-filled atomic orbitals localized on atoms, while Molecular Orbital Theory combines atomic orbitals to form delocalized molecular orbitals over the entire molecule.

Question 2

According to Valence Bond Theory, what is the geometry of methane (CH4) and which hybrid orbitals are involved?

Accepted Answer

Tetrahedral geometry; $$sp^3$$ hybrid orbitals

Question 3

Which equation is used in Molecular Orbital Theory to calculate the probability of finding an electron in a particular location?

Accepted Answer

$$\hat{H}\Psi = E\Psi$$

Question 4

What is the bond order for the diatomic helium molecule ($$He_2) $$according to Molecular Orbital Theory?

Accepted Answer

0

Question 5

Which type of bond allows free rotation around the bond axis?

Accepted Answer

$$\sigma$$ bond

Question 6

In formaldehyde ($$H_2CO$$), which orbitals are involved in forming the double bond between carbon and oxygen?

Accepted Answer

One $$\sigma$$ bond from $$sp^2$$ hybrid orbital and one $$\pi$$ bond from unhybridized $$p$$ orbital

Question 7

What is the bond angle predicted by unhybridized $$p$$ orbitals in $$H_2S$$ and how does it compare to the actual bond angle?

Accepted Answer

Predicted: $$90^\circ$$, Actual: $$92.1^\circ$$

Question 8

Which hybridization is required for phosphorus in $$PCl_5 to $$achieve its observed geometry?

Accepted Answer

$$sp^3d$

Question 9

How many $$sp^3$$ hybrid orbitals are formed when one $$s$$ and three $$p$$ orbitals mix?

Accepted Answer

Four

Question 10

Which statement about molecular orbitals is correct?

Accepted Answer

Molecular orbitals are formed by combining atomic orbitals and are delocalized over the entire molecule.

Question 11

What is the bond order for $$Li_2$$ according to Molecular Orbital Theory?

Accepted Answer

1

Question 12

Which hybridization is required for sulfur in $$SF_6 to $$achieve its observed geometry?

Accepted Answer

$$sp^3d^2$

Question 13

Which of the following best explains why $$CH_4$$ has a bond angle of $$109.5^\circ$$ instead of $$90^\circ$$?

Accepted Answer

The $$s$$ and $$p$$ orbitals hybridize to form four $$sp^3$$ orbitals arranged tetrahedrally.

Question 14

In acetylene ($$C_2H_2$$), what is the hybridization of the carbon atoms and how many $$\pi$$ bonds are present?

Accepted Answer

Each carbon is $$sp$$ hybridized with two $$\pi$$ bonds.

Question 15

Which type of molecular orbital results from constructive interference between atomic wavefunctions?

Accepted Answer

Bonding orbital

Question 16

What is the formula for calculating bond order in Molecular Orbital Theory?

Accepted Answer

$$	ext{Bond Order} = \frac{	ext{Number of electrons in bonding MOs} - 	ext{Number of electrons in antibonding MOs}}{2}$$

Question 17

Which theory is better at explaining resonance and magnetism in molecules with odd numbers of electrons?

Accepted Answer

Molecular Orbital Theory

Question 18

What is the hybridization of the central atom in a molecule with an octahedral geometry?

Accepted Answer

$$sp^3d^2$

Question 19

Which of the following is NOT a feature of Valence Bond Theory?

Accepted Answer

Uses the Schrödinger equation to combine atomic orbitals into molecular orbitals

Valence Bond and Molecular Orbital Theory: Chemical Bonding II

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