$$\text{FC} = V - N - \frac{B}{2}$$

Question 1

Which of the following best describes the trend in electronegativity across a period in the periodic table?

Accepted Answer

Electronegativity increases from left to right.

Question 2

Given the electronegativity values: H (2.1), Cl (3.0), and Na (0.9), which bond is most ionic?

Accepted Answer

$$	ext{Na—Cl}$$

Question 3

Which of the following molecules will have a net dipole moment?

Accepted Answer

$$	ext{H}_2	ext{O}$$

Question 4

What is the formal charge on the central atom in the Lewis structure of $$	ext{NO}_3^-$$?

Accepted Answer

$$0$$

Question 5

Which of the following bonds is considered nonpolar covalent?

Accepted Answer

$$	ext{Cl—Cl}$$

Question 6

Draw the Lewis structure for $$	ext{CO}_3$$^{2-}$$ and determine the number of resonance structures.

Accepted Answer

3

Question 7

Which of the following molecules violates the octet rule by having an expanded octet?

Accepted Answer

$$	ext{SF}_6$$

Question 8

What is the correct formula to calculate the formal charge (FC) on an atom?

Accepted Answer

$$	ext{FC} = V - N - \frac{B}{2}$$

Question 9

Which of the following best explains why $$	ext{SO}_2$$ has resonance structures?

Accepted Answer

Because the double bond can be placed on either oxygen, and both structures are equivalent.

Question 10

Which of the following molecules is polar due to its molecular geometry?

Accepted Answer

$$	ext{NH}_3$$

Question 11

A molecule of $$	ext{BrF} is $$placed in an electric field. What happens to the molecule?

Accepted Answer

It aligns with the field due to its dipole moment.

Question 12

Which of the following pairs will form a polar covalent bond?

Accepted Answer

$$	ext{C—O}$$

Question 13

How many valence electrons are present in the Lewis structure of $$	ext{CH}_3	ext{OH} ($$methanol)?

Accepted Answer

20

Question 14

Which of the following ions has three equivalent resonance structures?

Accepted Answer

$$	ext{NO}_3^-$$

Question 15

Which of the following molecules or ions has a central atom with a formal charge of zero in its most stable Lewis structure?

Accepted Answer

$$	ext{CO}_3$$^{2-}$$

Question 16

Which of the following best describes the bond in $$	ext{H—F}$$?

Accepted Answer

Polar covalent

Question 17

Which of the following molecules has an expanded octet on the central atom?

Accepted Answer

$$	ext{PCl}_5$$

Question 18

Which of the following is the best Lewis structure for $$	ext{ClO}_3^-$$ based on formal charges?

Accepted Answer

The structure with one double bond and two single bonds, minimizing formal charges.

Question 19

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

Accepted Answer

$$	ext{CO}_2$$

Question 20

Which of the following best explains why $$	ext{Cl}_2 is a $$nonpolar molecule?

Accepted Answer

Because the two atoms have identical electronegativities.

Electronegativity, Bond Polarity, and Lewis Structures: Study Guide

Study Guide - Practice Questions