What Are the Relationships between Acidity and Molecular Structure

5 What Are the Relationships between Acidity and Molecular Structure  

Now let us examine the relationship between the acidity of organic compounds and their molecular structure. The most important factor in determining the relative acidities of organic acids is the relative stability of the anion. A , formed when the acid, HA, transfers a proton to a base. We can understand the relationship involved by considering (A) the electronegativity of the atom bonded to H, (B) resonance, (C) tbe inductive effect, and (D) the size and delocalization of charge on A . We will look at each of these factors briefly in this chapter. We will study them more fully in later chapters when we deal with particular functional groups. 

Electronegativity Acidity of HA within a Period of the Periodic Table 

Caution Electronegativity is the major factor when comparing the stability of negatively charged atoms in the same period of the Periodic Table. Other factors, which we will discuss in Section 2.5D and in future chapters, will become significant when comparing atoms in the same group (vertical column) of the Periodic Table. 

Carboxylic acids are weak acids Values of for most unsubstituted carboxylic acids fall 

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