The most suitable reagent for the given conversion is

In the given reaction,the reactant is $\gamma$-valerolactone. Predict the product $[X]$ for the reaction: $\text{Reactant} \xrightarrow{H_2O/H^{+}} [X]$.

What is the major product of the following reaction sequence: $CH_3-CH_2-Br$ $\xrightarrow{KCN}$ $\xrightarrow[H_2O]{OH^{-}}$ $\xrightarrow{PCl_5, \Delta} \text{product}$?

How many organic products will be formed when the following compound undergoes decarboxylation?
(Image: $A$ substituted cyclopentane ring with two $-COOH$ groups at the same carbon atom,and two $-CH_3$ groups at adjacent carbons.)

Which is the strongest acid? ($pK_a$ value is given in the bracket)

Give reactions of carboxylic acids in which $C-OH$ bond breaks. $OR$ Give methods of preparation for $(a)$ anhydride $(b)$ ester $(c)$ acid chloride and $(d)$ amide from carboxylic acids.