How can acid anhydride be prepared by dehydration of carboxylic acid? Give reaction.

Arrange the following compounds in increasing order of their property as indicated:

$\mathrm{C}{\mathrm{H}}_3\mathrm{C}{\mathrm{H}}_2\mathrm{C}\mathrm{H}\left(\mathrm{B}\mathrm{r}\right)\mathrm{C}\mathrm{O}\mathrm{O}\mathrm{H}, \mathrm{C}{\mathrm{H}}_3\mathrm{C}\mathrm{H}\left(\mathrm{B}\mathrm{r}\right)\mathrm{C}{\mathrm{H}}_2\mathrm{C}\mathrm{O}\mathrm{O}\mathrm{H}, {\left(\mathrm{C}{\mathrm{H}}_3\right)}_2\mathrm{C}\mathrm{H}\mathrm{C}\mathrm{O}\mathrm{O}\mathrm{H}, \mathrm{C}{\mathrm{H}}_3\mathrm{C}{\mathrm{H}}_2\mathrm{C}{\mathrm{H}}_2\mathrm{C}\mathrm{O}\mathrm{O}\mathrm{H}$ (acid strength).

Identify $\mathrm{A}, \mathrm{B}$ and $\mathrm{C}$

Draw the structure of following compound

3-bromo-4-phenylpentanoic acid