$C_3H_9N$ represents

When you ingest aspirin,it passes through your stomach,which has an acidic $pH$,before traveling through the basic environment of your intestine. Provide the structure form as it exists in the intestine.

$A$ student has planned to prepare acetanilide from aniline using acetic anhydride. The student has started from $9.3 \ g$ of aniline. However, the student has managed to obtain $11 \ g$ of dry acetanilide. The $\%$ yield of this reaction is $.....$ (in $\%$)

$Ph-NH_2$ $\xrightarrow{CH_3Cl \ (2 \ mole)} (A)$ $\xrightarrow{Ph-N_2^+ Cl^-} (B) \ (\text{major})$
Butter yellow is the product of the above reaction.

Which of the following sets of reagents, used in the order shown, would enable the preparation of $p$-chlorophenol from $p$-chloronitrobenzene?

The product $(C)$ of the following reaction is: