Question 1

Which of the following best explains why HF molecules align themselves in an electric field, as shown in the image?

Accepted Answer

HF molecules are polar, so the partial positive and negative charges align with the electric field.

Question 2

Which element is the most electronegative according to the periodic trend shown in the provided images?

Accepted Answer

Fluorine

Question 3

Given the Lewis structure for water ($$\mathrm{H_2O}$$), what is the molecular geometry and why?

Accepted Answer

Bent, because there are two bonding pairs and two lone pairs on oxygen.

Question 4

Which of the following bonds is the most polar based on electronegativity differences?

Accepted Answer

$$\mathrm{Sr-F}$$

Question 5

What is the formal charge on the oxygen atom in the hydroxide ion ($$\mathrm{OH^-}$$)?

Accepted Answer

$$-1$$

Question 6

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

Accepted Answer

$$\mathrm{CO_2$}$$

Question 7

Which of the following elements can expand its octet?

Accepted Answer

P

Question 8

What is the bond order and relative bond energy for the carbon-carbon bond in ethyne ($$\mathrm{C_2H_2}$$)?

Accepted Answer

Bond order 3, highest bond energy

Question 9

Which of the following best describes the electron geometry and molecular geometry of $$\mathrm{NH_3$}$$?

Accepted Answer

Tetrahedral electron geometry, trigonal pyramidal molecular geometry

Question 10

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

Accepted Answer

$$\mathrm{BF_3$}$$

Question 11

A molecule has three electron groups around the central atom, one of which is a lone pair. What is the molecular geometry?

Accepted Answer

Bent

Question 12

Which of the following best explains why oil and water do not mix?

Accepted Answer

Oil is nonpolar and water is polar, so they do not interact favorably.

Question 13

What is the formal charge on the carbon atom in the cyanide ion ($$\mathrm{CN^-}$$)?

Accepted Answer

$$-1$$

Question 14

Which of the following statements about resonance structures is correct?

Accepted Answer

The actual molecule is a hybrid of all valid resonance structures.

Question 15

Which of the following molecules has a linear molecular geometry?

Accepted Answer

$$\mathrm{CO_2$}$$

Question 16

Which of the following best describes the relationship between bond order, bond length, and bond energy?

Accepted Answer

As bond order increases, bond length decreases and bond energy increases.

Question 17

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

Accepted Answer

$$\mathrm{NH_3$}$$

Question 18

What is the correct Lewis structure for the cyanate ion ($$\mathrm{OCN^-}) $$that best follows the rules for minimizing formal charge?

Accepted Answer

O single bonded to C, triple bonded to N, with negative charge on O

Question 19

Which of the following is a correct step in drawing a Lewis structure for a polyatomic ion?

Accepted Answer

Add electrons for each negative charge.

Question 20

Which of the following molecules has an expanded octet?

Accepted Answer

$$\mathrm{$$XeF_2$$}$$

Chemical Bonding I: Electronegativity, Lewis Structures, Resonance, and Molecular Geometry

Study Guide - Practice Questions