Final answer:
The correct decreasing reactivity order for the given compounds towards hydrolysis is acetic anhydride (CH₃CO)2O, which is more reactive than acetamide CH₃CONH₂.
Step-by-step explanation:
The question concerns the reactivity order of certain carboxylic acid derivatives towards hydrolysis under identical conditions.
According to reactivity trends, acyl halides are the most reactive, followed by anhydrides, esters, amides, and then carboxylic acids. Specifically, the reactivity of anhydrides (such as (CH₃CO)₂O, acetic anhydride) is higher compared to amides (such as CH₃CONH₂, acetamide), making acetic anhydride more susceptible to hydrolysis.