Q: Which of the following best describes the difference between a $$ ext{\sigma} ($$sigma) bond and a $$ ext{\pi} (pi) $$bond?

$$\text{\sigma}$$ bonds result from end-to-end overlap, while $$\text{\pi}$$ bonds result from side-to-side overlap.

Q: A patient is exposed to carbon monoxide ($$CO$$), which binds to hemoglobin via a covalent bond. Which type of orbital overlap is responsible for the bond between carbon and oxygen in $$CO$$?

One $$\text{\sigma}$$ bond and two $$\text{\pi}$$ bonds

Question 1

Which of the following best describes the relationship between a 2-dimensional Lewis structure and its corresponding 3-dimensional electron-domain geometry for methane ($$CH_4$$)?

Accepted Answer

The Lewis structure shows four single bonds around carbon, and the 3D geometry is tetrahedral.

Question 2

What is the electron-domain geometry predicted by the VSEPR model for a molecule with five electron domains around the central atom?

Accepted Answer

Trigonal bipyramidal

Question 3

Which of the following molecules is predicted to be nonpolar based on its geometry and bond dipole moments?

Accepted Answer

Carbon dioxide ($$CO_2)$$

Question 4

A molecule has the Lewis structure of $$AX_2E_2 ($$where $$A is $$the central atom, $$X is a $$bonded atom, and $$E is a $$lone pair). What is the predicted molecular geometry using the VSEPR model?

Accepted Answer

Bent

Question 5

Which statement best explains the role of orbital overlap in the formation of a covalent bond?

Accepted Answer

Covalent bonds form when atomic orbitals overlap and electrons are shared between atoms.

Question 6

What is the hybridization of the central atom in $$BF_3$$?

Accepted Answer

$$sp^2$$

Question 7

Which of the following best describes the orbital overlap that forms a $$	ext{pi}$$ ($$	ext{\pi}) $$bond?

Accepted Answer

Side-to-side overlap of two $$p$$ orbitals

Question 8

Which molecule has a trigonal pyramidal molecular geometry according to the VSEPR model?

Accepted Answer

Ammonia ($$NH_3)$$

Question 9

A molecule has a central atom with $$sp^3d^2$ hybridization. What is the expected electron-domain geometry?

Accepted Answer

Octahedral

Question 10

Which of the following molecules is polar due to its molecular geometry, even though all the bonds are identical?

Accepted Answer

Water ($$H_2O)$$

Question 11

Which of the following is the correct Lewis structure for $$CO_2$$ and its corresponding 3D geometry?

Accepted Answer

Lewis structure: O=C=O; Geometry: Linear

Question 12

Which hybrid orbitals are involved in the bonding of the central atom in $$NH_3$$?

Accepted Answer

$$sp^3$$

Question 13

Which of the following best describes the difference between a $$	ext{\sigma} ($$sigma) bond and a $$	ext{\pi} (pi) $$bond?

Accepted Answer

$$	ext{\sigma}$$ bonds result from end-to-end overlap, while $$	ext{\pi}$$ bonds result from side-to-side overlap.

Question 14

A patient is exposed to carbon monoxide ($$CO$$), which binds to hemoglobin via a covalent bond. Which type of orbital overlap is responsible for the bond between carbon and oxygen in $$CO$$?

Accepted Answer

One $$	ext{\sigma}$$ bond and two $$	ext{\pi}$$ bonds

Question 15

Which of the following molecules has a central atom with $$sp^3d$ hybridization?

Accepted Answer

Phosphorus pentachloride ($$PCl_5)$$

Question 16

Which of the following best explains why $$CO_2 is $$nonpolar even though it contains polar bonds?

Accepted Answer

The molecule is linear, so the bond dipoles cancel each other.

Question 17

Which of the following molecules has a square planar geometry according to the VSEPR model?

Accepted Answer

Xenon tetrafluoride ($$XeF_4)$$

Question 18

Which of the following is a correct statement about the hybridization of the central atom in $$SF_6$$?

Accepted Answer

$$sp^3d^2$

Question 19

Which of the following molecules has both $$	ext{\sigma}$$ and $$	ext{\pi}$$ bonds?

Accepted Answer

Ethylene ($$C_2H_4)$$

Question 20

A chemist observes that $$SO_2 is a $$polar molecule. Which feature of its structure is primarily responsible for its polarity?

Accepted Answer

It has a bent molecular geometry due to lone pairs on the central atom.

Molecular Geometry and Bonding Theories: VSEPR, Polarity, Hybridization, and Orbital Overlap

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