Which drug is used to reduce mental tension and induce mental calmness?

Barbiturates are hypnotic agents. Veronal is a derivative of barbituric acid. It can be synthesized by the following sequence,then the structure of veronal $(P)$ is :
$CH_2(CO_2Et)_2$ $\xrightarrow[EtI]{EtO^-}$ $\xrightarrow[EtI]{EtO^-}$ $\xrightarrow{Urea}$ $(P)$

The artificial sweetener which is stable under cold conditions only is

Which of the following is an analgesic?

Aspirin is a

Chloramphenicol is a/an . . . . . . .