Basically, barbiturates are the derivatives of barbituric acid, which is veronal, amytal, nembutal, luminal and seconal. These are an important class of tranquilizers.

(a) STRUCTURE OF VERONAL

(b) STRUCTURE OF AMYTAL

(c) STRUCTURE OF NEMBUTAL

(d) STRUCTURE OF LUMINAL

(e) STRUCTURE OF SECONAL

Let’s discuss a little about tranquilizers too.

TRANQUILIZERS: These are a class of chemical compounds used for the treatment of stress, and mild or even severe mental diseases. These relieve anxiety, stress, and irritability or excitement by inducing a sense of well-being.

Also, barbiturates are hypnotic which implies they are sleep producing agents.

Hence, options (i) and (ii) are correct about barbiturates. Options (iii) and (iv) are incorrect.