Final answer:
The reactivity of carboxylic acids and their derivatives in nucleophilic acyl substitution reactions increases in the following order: carboxylate anion, amide, ester, anhydride, acid chloride.
Step-by-step explanation:
The correct order of reactivity from lowest to highest for carboxylic acids and their derivatives is as follows: carboxylate anion > amide > ester > anhydride > acid chloride. This sequence represents their reactivity as acyl substrates in nucleophilic acyl substitution reactions. The reactivity increases because groups that are higher in this order can be converted more easily into groups that are lower in the order. The key factors affecting this reactivity include the ability of the leaving group to leave and the stability of the resulting acyl intermediate.