The number of stereoisomers possible for the following compound is $CH_3-CH=CH-CH(Br)-CH_2-CH_3$

Identify $B$ in the following tautomerization reaction:
$4\text{-pyridone} \xrightarrow{KOH} B$

Which of the following is an $E$ isomer?

Identify the correct sequence for True and False.
$(I)$ Only compounds with chiral centers can be optically active.
$(II)$ Absence of elements of symmetry is the reason for a molecule's optical activity.
$(III)$ All organic compounds contain carbon $\&$ hydrogen.
$(IV)$ Different canonical forms of a molecule represent the actual structures of a molecule which has resonance in it.

If a carbon atom is attached to $-H, -OH, -COOH$ and $-OCO^{-}C_2H_5$ groups,the number of chiral $C$ atoms in the molecule is:

Which of the following pairs does not exhibit isomerism?