Question 1

Which of the following best describes the main advantage of using the Lewis model to represent molecules?

Accepted Answer

It provides a simple way to predict molecular stability and bonding patterns.

Question 2

Which statement correctly explains why HIV-protease inhibitors are effective in treating HIV?

Accepted Answer

They bind to the active site of HIV-protease, preventing the virus from replicating.

Question 3

According to the Lewis model, what is the maximum number of valence electrons that can surround a main-group element (except hydrogen and helium) to achieve stability?

Accepted Answer

$$8$$

Question 4

Which of the following is the correct Lewis structure for magnesium oxide ($$\mathrm{MgO}$$)?

Accepted Answer

$$\mathrm{Mg}^{2+} \ [\cdot\cdot O \cdot\cdot]^{2-}$$

Question 5

Which of the following molecules is an example of a diatomic molecule formed due to the sharing of electrons to achieve a duet configuration?

Accepted Answer

$$\mathrm{H}_2$$

Question 6

What is the correct Lewis structure for carbon dioxide ($$\mathrm{CO}_2$$)?

Accepted Answer

$$O=C=O$$

Question 7

Which of the following best describes the difference between ionic and covalent bonds according to the Lewis model?

Accepted Answer

Ionic bonds involve the transfer of electrons, while covalent bonds involve the sharing of electrons.

Question 8

Which molecule below is an example of a molecule with a triple bond in its Lewis structure?

Accepted Answer

$$\mathrm{N}_2$$

Question 9

Which of the following statements about resonance structures is correct?

Accepted Answer

The true structure of a molecule with resonance is an average of all possible resonance structures.

Question 10

Which of the following best explains why water ($$\mathrm{H}_2O) is a $$polar molecule?

Accepted Answer

It has polar bonds that do not cancel due to its bent molecular geometry.

Question 11

What is the molecular geometry of methane ($$\mathrm{CH}_4) $$according to VSEPR theory?

Accepted Answer

Tetrahedral

Question 12

Which of the following statements about electronegativity is true?

Accepted Answer

Fluorine is the most electronegative element.

Question 13

A molecule has three electron groups around the central atom and no lone pairs. What is its electron geometry and approximate bond angle?

Accepted Answer

Trigonal planar, $$120^\circ$$

Question 14

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

Accepted Answer

Water molecules are polar and oil molecules are nonpolar, causing them to separate.

Question 15

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

Accepted Answer

Add one electron for each negative charge.

Question 16

Which of the following molecules has a trigonal pyramidal molecular geometry?

Accepted Answer

$$\mathrm{NH}_3$$

Question 17

Which of the following best describes a polar covalent bond?

Accepted Answer

A bond in which electrons are shared unequally due to a difference in electronegativity.

Question 18

Which of the following is an exception to the octet rule?

Accepted Answer

$$\mathrm{BF}_3$$, where boron has only 6 electrons around it.

Question 19

Which of the following best explains why soap can remove grease from your hands?

Accepted Answer

Soap molecules have both a polar head that interacts with water and a nonpolar tail that interacts with grease.

Question 20

Which of the following is the correct Lewis structure for the cyanide ion ($$\mathrm{CN}^-$$)?

Accepted Answer

$$[:C\equiv N:]^{-}$$

Chapter 10: Chemical Bonding – Lewis Structures and Bonding Theories

Guida di studio - Domande di pratica

Study guide - Flashcard