Carboxylic acids and acid chlorides are both functional groups that can undergo nucleophilic substitution reactions. However, they differ significantly in their reactivity towards nucleophiles.Reactivity:Acid chlorides are much more reactive towards nucleophilic substitution reactions compared to carboxylic acids. This is because acid chlorides have a better leaving group chloride ion than carboxylic acids hydroxide ion .Factors affecting reactivity:1. Electronegativity of the leaving group: The leaving group in acid chlorides is a chloride ion Cl- , which is more electronegative than the hydroxide ion OH- in carboxylic acids. The higher electronegativity of the chloride ion stabilizes the negative charge better when it leaves, making the reaction more favorable.2. Resonance stabilization: In carboxylic acids, the carbonyl group has resonance stabilization with the hydroxyl group, which makes the carboxylic acid less reactive towards nucleophilic substitution. In acid chlorides, there is no such resonance stabilization, making them more susceptible to nucleophilic attack.3. Steric hindrance: Carboxylic acids have a larger and more sterically hindered leaving group OH- compared to the smaller chloride ion in acid chlorides. This makes it more difficult for nucleophiles to approach and attack the carbonyl carbon in carboxylic acids, reducing their reactivity.4. Inductive effect: The electronegative chlorine atom in acid chlorides has an electron-withdrawing inductive effect, which increases the partial positive charge on the carbonyl carbon. This makes the carbonyl carbon more susceptible to nucleophilic attack, increasing the reactivity of acid chlorides.In summary, acid chlorides are more reactive towards nucleophilic substitution reactions than carboxylic acids due to the presence of a better leaving group, lack of resonance stabilization, reduced steric hindrance, and the inductive effect of the chlorine atom.