Question 48 E - Chemistry (OpenStax)

Question

In terms of the bonds present, explain why acetic acid, \(C{H_3}C{O_2}H\), contains two distinct types of carbon-oxygen bonds, whereas the acetate ion, formed by loss of a hydrogen ion from acetic acid, only contains one type of carbon-oxygen bond. The skeleton structures of these species are shown:

Step-by-Step Solution

Answer

Acetic acid, \(C{H_3}C{O_2}H\), contains two distinct types of carbon-oxygen bonds, whereas the acetate ion, only contains one type of carbon-oxygen bond as there is resonance happening in acetate ion.

Step 1: Concept Introduction

Chemical bonding is a formation of chemical compound by initiating a chemical link between two or more atoms, molecules, or ions. The atoms in the consequent molecule are retained together by chemical bonds.

Step 2: Bonds in Acetic Acid and Acetate Ion

The acetic acid molecule contains a \({\rm{C - O}}\) double bond and a \({\rm{C - O}}\) single bond.

There is resonance happening in case of acetate ion and it is described by two resonance structures that average the two \({\rm{C - O}}\) bonds.

So, it is because of resonance that acetate ion contains only one type of carbon-oxygen bond (average of two \({\rm{C - O}}\) bonds).

 

Therefore, both the acetate compounds contain different number of bonds due to resonance.