Question 1

Which of the following best explains why the lattice energy of $$\mathrm{MgO} is $$significantly higher than that of $$\mathrm{NaCl}$$?

Accepted Answer

Because $$\mathrm{MgO}$$ has ions with higher charges, leading to stronger electrostatic attraction according to Coulomb's Law.

Question 2

Which step in the Born-Haber cycle involves the energy required to convert a solid metal into gaseous atoms?

Accepted Answer

Sublimation energy

Question 3

Which of the following molecules contains a polar covalent bond?

Accepted Answer

$$\mathrm{H_2O}$$

Question 4

Given the following electronegativities: H (2.1), C (2.5), N (3.0), O (3.5), which bond is the most polar?

Accepted Answer

$$\mathrm{O-H}$$

Question 5

Which of the following best describes the difference between ionic and covalent bonds?

Accepted Answer

Ionic bonds involve the transfer of electrons from one atom to another, while covalent bonds involve the sharing of electrons.

Question 6

Which of the following Lewis structures for $$\mathrm{CO_2$} is $$correct based on the octet rule and formal charges?

Accepted Answer

O=C=O, with all atoms having zero formal charge.

Question 7

Which molecule violates the octet rule by having an incomplete octet?

Accepted Answer

$$\mathrm{BF_3$}$$

Question 8

What is the formal charge on the nitrogen atom in the Lewis structure of $$\mathrm{NH_4$^+}$$?

Accepted Answer

0

Question 9

Which of the following molecules has an expanded octet?

Accepted Answer

$$\mathrm{SF_6$}$$

Question 10

What is the electron domain geometry and molecular geometry of $$\mathrm{CH_4$}$$?

Accepted Answer

Electron domain geometry: tetrahedral; Molecular geometry: tetrahedral

Question 11

Which hybridization corresponds to a molecule with a trigonal planar electron domain geometry?

Accepted Answer

$$\mathrm{sp^2$}$$

Question 12

A molecule has three bonding pairs and one lone pair around the central atom. What is its molecular geometry?

Accepted Answer

Trigonal pyramidal

Question 13

Which of the following statements about electronegativity is correct?

Accepted Answer

Electronegativity decreases down a group and increases across a period.

Question 14

Which of the following molecules contains an odd number of electrons?

Accepted Answer

$$\mathrm{NO}$$

Question 15

Which of the following best describes the hybridization of the central atom in $$\mathrm{$$PCl_5$$}$$?

Accepted Answer

$$\mathrm{sp^3$d}$$

Question 16

A chemist is designing a new ionic compound for use in batteries. Which property is most important for maximizing the lattice energy of the compound?

Accepted Answer

Using ions with small radii and high charges

Question 17

Which of the following is the correct Lewis structure for $$\mathrm{O_3$} ($$ozone) with minimized formal charges?

Accepted Answer

O=O–O, with one double bond and one single bond, and formal charges of 0, +1, and -1.

Question 18

Which molecule has a bond angle closest to $$109.5^\circ$$?

Accepted Answer

$$\mathrm{NH_3$}$$

Question 19

Which of the following best explains why $$\mathrm{SF_6$}$$ can have more than eight electrons around the central sulfur atom?

Accepted Answer

Sulfur has available d orbitals that allow for an expanded octet.

Question 20

Which of the following molecules is nonpolar despite having polar bonds?

Accepted Answer

$$\mathrm{CO_2$}$$

Chemical Bonding and Molecular Structure: Chapters 8 & 9 Study Guide

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