Identify the product formed in the following reaction: $(CH_3CO)_2O \xrightarrow{H_2O} \text{Product}$

Consider the following sequence of reactions. The major product $P$ is:

The descending order of acidity among the following compounds is:

Identify the reagent used in the following reaction: $\text{Benzoic acid} \xrightarrow[\Delta]{\text{Reagent}} \text{Benzoyl chloride} + \text{Phosphorus oxychloride} + \text{Hydrogen chloride}$.

Which one of the following orders of acid strength is correct?

Which is the weakest acid among the following?