Covalent Bonds

Chapter 8: 4-6 Homework

Reading Preparation
WebLecture
Study Activity
Preparation work for chat
Online Quiz
Lab Instructions

Reading Preparation

Textbook assignment: Read Kotz and Triechel, Chemistry and Chemical Reactivity Chapter 8: Section 4-6.

Study Notes

8.4: Resonance occurs when two possible electron configurations have an equal probability. There is no force or causal rule for an electron to be in one rather than the other orbital, so the rules of quantum mechanics state that the electron will spends time in both.
8.5: The octet rule states that molecules have a tendency to form chemical bonds so that eight electrons, usually the s and p electrons in the outermost energy level, surround each atom, and allows us to predict Lewis structures for many different molecules and ions. But there are always exceptions! The extremely high electronegativity in fluorine allows it to grab and hang onto more than 8 electrons at a time. As a result, fluorine will form Lewis structures in which the central atom (Fl) exceeds an octet. NO and NO₂ form stable molecules with single unpaired electrons.
8.6: The VSEPR ( valence shell electron-pair repulsion) model allows us to predict the shapes of covalent molecules and polyatomic ions. All molecular models are based on the idea that electron pairs, whether in bonds or lone electrons, repel each other and seek to be as far as part as possible. These principles predict molecular shapes that are linear, trigonal-planar (three in the same plane), tetrahedral, trigonal-bipyramidal, or octahedral. In each case, the available electron pairs seek to be equidistant from each other.

There are no equations for these sections.

Web Lecture

Read the following weblecture before chat: Covalent Bonds.

Study Activity

Videos for Chapter 8: Chemical Bonds and Molecular Geometry

Review the Videos at Thinkwell Video Lessons.

Under "Chemical Bonding: Fundamental Concepts: Resonance Structures and Formal Charge"
- Resonance Structures
Under "Molecular Geometry and Chemical Bonding Theory: Molecular Geometry and VESPER Theory"
- Valence-Shell Electron-Pair Repulsion Theory
- Molecular Shapes for Steric Numbers 2-4
- Molecular Shapes for Steric Numbers 5 & 6
- Predicting Molecular Characteristics Using VESPR Theory

Review the rules on How to draw Resonance Contributors and see if you can correctly draw the Lewis Dot structures for the ions in the Exercises at the end of the page.

Chat Preparation Activities

Essay question: The Moodle forum for the session will assign a specific study question for you to prepare for chat. You need to read this question and post your answer before chat starts for this session.
Mastery Exercise: The Moodle Mastery exercise for the chapter will contain sections related to our chat topic. Try to complete these before the chat starts, so that you can ask questions.

Chapter Quiz

There is no chapter quiz YET.

Lab Work

LAB #6 GUIDED INQUIRY: Using qualitative methods to differentiate covalent and ionic bonds. -- Phase II

Carry out the experiment you designed in Phase I, and collect your data in a suitable format. Perform your initial analysis and determine whether you need to repeat your experiment and/or refine your procedure.

References

APGIE Investigation 6: Bonding in Solids: What’s in that Bottle?
IGHCE Lab 19.3-4 Qualitative Analysis of Inorganic Cations and Anions
Alternative Lab: Molecular Geometry

© 2005 - 2024 This course is offered through Scholars Online, a non-profit organization supporting classical Christian education through online courses. Permission to copy course content (lessons and labs) for personal study is granted to students currently or formerly enrolled in the course through Scholars Online. Reproduction for any other purpose, without the express written consent of the author, is prohibited.