Polar Covalent Bonds Acids and Bases

VVe saw in the last chapter how covalent bonds between atoms are described, and we looked at the valence bond model, which uses hybrid orbitals to account for the observed shapes of organic molecules. Before going on to a systematic study of organic chemistry, however, we still need to review a few fundamental topics. In particular, we need to look more closely at how electrons are distributed in covalent bonds and at some of the consequences that arise when the electrons in a bond are not shared equally between atoms. 

Understanding organic chemistry means knowing not just what happens but also why and how it happens. In this chapter, we ll look some of the basic ways chemists use to describe and account for chemical reactivity, thereby providing a foundation for understanding the specific reactions discussed in subsequent chapters. 

Problem 2.1 Which element in each of the following pairs is more electronegative  

Problem 2.2 Use the 6-i-/f - convention to show the direction of expected polarity for each of the bonds indicated. 

Problem 2.4 Look at the following electrostatic potential map of chloromethane, and tell the direction of polarization of the C-Cl bond  

Although some bonds are totally ionic and some are totally covalent, most chemical bonds are polar covalent bonds. 

In these bonds, electrons are attracted to one atom more than to the other atom. 

The difference in EN between two elements can be used to predict the polarity of a bond. 

The tail of the arrow is electron-poor, and the head of the arrow is electron-rich. 

Electrostatic potential maps are also used to show electron-rich (red) and electron-poor (blue) regions of molecules. 

9 Predicting Acid-Base Reactions from p/Cg Values 

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CHAPTER 2 Polar Covalent Bonds Acids and Bases... 

Chapter 2, Polar Covalent Bonds Acids and Bases—A new Section 2.13 on non-covalent interactions has been added. 

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