The number of $-OH$ groups present in the structures of bithionol,terpineol and chloroxylenol is respectively:

Which of the following is not an antibiotic?

Penicillin was first discovered by

Which of the following is an incorrect match?

$A$ chemist has $4$ samples of artificial sweetener $A, B, C$,and $D$. To identify these samples,he performed certain experiments and noted the following observations:
$(i)$ $A$ and $D$ both form blue-violet colour with ninhydrin.
$(ii)$ Lassaigne extract of $C$ gives positive $AgNO_{3}$ test and negative $Fe_{4}[Fe(CN)_{6}]_{3}$ test.
$(iii)$ Lassaigne extract of $B$ and $D$ gives positive sodium nitroprusside test.
Based on these observations,which option is correct?

Match the compounds given in Column-$I$ with the effects given in Column-$II$.

Column-$I$	Column-$II$
$A$. Chloramphenicol	$1$. Malaria
$B$. Thyroxine	$2$. Anaesthetic
$C$. Chloroquine	$3$. Typhoid fever
$D$. Chloroform	$4$. Goiter
$ $	$5$. Blood substituent